CWE-835
AllowedLoop with Unreachable Exit Condition ('Infinite Loop')
Abstraction: Base · Status: Incomplete
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
1060 vulnerabilities reference this CWE, most recent first.
GHSA-C33M-22CR-J9X4
Vulnerability from github – Published: 2022-05-24 17:01 – Updated: 2024-11-26 15:50Designate does not enforce the DNS protocol limit concerning record set sizes
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "designate"
},
"versions": [
"2015.1.0b2"
]
}
],
"aliases": [
"CVE-2015-5694"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": true,
"github_reviewed_at": "2024-11-21T22:15:16Z",
"nvd_published_at": "2019-11-22T15:15:00Z",
"severity": "MODERATE"
},
"details": "Designate does not enforce the DNS protocol limit concerning record set sizes",
"id": "GHSA-c33m-22cr-j9x4",
"modified": "2024-11-26T15:50:36Z",
"published": "2022-05-24T17:01:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-5694"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2015-5694"
},
{
"type": "PACKAGE",
"url": "https://github.com/openstack/designate"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/designate/PYSEC-2019-243.yaml"
},
{
"type": "WEB",
"url": "https://security-tracker.debian.org/tracker/CVE-2015-5694"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2015/07/28/11"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2015/07/29/6"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U",
"type": "CVSS_V4"
}
],
"summary": "Designate does not enforce the DNS protocol limit concerning record set sizes"
}
GHSA-C47W-GGCW-5493
Vulnerability from github – Published: 2026-02-04 18:30 – Updated: 2026-03-18 15:30In the Linux kernel, the following vulnerability has been resolved:
fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()
Above the while() loop in wait_sb_inodes(), we document that we must wait for all pages under writeback for data integrity. Consequently, if a mapping, like fuse, traditionally does not have data integrity semantics, there is no need to wait at all; we can simply skip these inodes.
This restores fuse back to prior behavior where syncs are no-ops. This fixes a user regression where if a system is running a faulty fuse server that does not reply to issued write requests, this causes wait_sb_inodes() to wait forever.
{
"affected": [],
"aliases": [
"CVE-2026-23109"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-04T17:16:21Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()\n\nAbove the while() loop in wait_sb_inodes(), we document that we must wait\nfor all pages under writeback for data integrity. Consequently, if a\nmapping, like fuse, traditionally does not have data integrity semantics,\nthere is no need to wait at all; we can simply skip these inodes.\n\nThis restores fuse back to prior behavior where syncs are no-ops. This\nfixes a user regression where if a system is running a faulty fuse server\nthat does not reply to issued write requests, this causes wait_sb_inodes()\nto wait forever.",
"id": "GHSA-c47w-ggcw-5493",
"modified": "2026-03-18T15:30:39Z",
"published": "2026-02-04T18:30:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23109"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3f4ed5e2b8f111553562507ad6202432c7c57731"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f9a49aa302a05e91ca01f69031cb79a0ea33031f"
}
],
"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"
}
]
}
GHSA-C4J8-6XXF-P927
Vulnerability from github – Published: 2022-05-13 01:48 – Updated: 2022-05-13 01:48A flaw was found in the Linux kernel present since v4.0-rc1 and through v4.13-rc4. A crafted network packet sent remotely by an attacker may force the kernel to enter an infinite loop in the cipso_v4_optptr() function in net/ipv4/cipso_ipv4.c leading to a denial-of-service. A certain non-default configuration of LSM (Linux Security Module) and NetLabel should be set up on a system before an attacker could leverage this flaw.
{
"affected": [],
"aliases": [
"CVE-2018-10938"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-08-27T13:29:00Z",
"severity": "HIGH"
},
"details": "A flaw was found in the Linux kernel present since v4.0-rc1 and through v4.13-rc4. A crafted network packet sent remotely by an attacker may force the kernel to enter an infinite loop in the cipso_v4_optptr() function in net/ipv4/cipso_ipv4.c leading to a denial-of-service. A certain non-default configuration of LSM (Linux Security Module) and NetLabel should be set up on a system before an attacker could leverage this flaw.",
"id": "GHSA-c4j8-6xxf-p927",
"modified": "2022-05-13T01:48:59Z",
"published": "2022-05-13T01:48:59Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-10938"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10938"
},
{
"type": "WEB",
"url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=40413955ee265a5e42f710940ec78f5450d49149"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2018/10/msg00003.html"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3797-1"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3797-2"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2018/dsa-4308"
},
{
"type": "WEB",
"url": "http://seclists.org/oss-sec/2018/q3/179"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/105154"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1041569"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-C59P-WQ67-24WX
Vulnerability from github – Published: 2025-01-21 19:58 – Updated: 2025-01-21 19:58Summary
This vulnerability allows a user to maneuver the Webfinger mechanism to perform a GET request to any internal resource on any Host, Port, URL combination regardless of present security mechanisms, and forcing the victim’s server into an infinite loop causing Denial of Service. Moreover, this issue can also be maneuvered into performing a Blind SSRF attack.
Details
The Webfinger endpoint takes a remote domain for checking accounts as a feature, however, as per the ActivityPub spec (https://www.w3.org/TR/activitypub/#security-considerations), on the security considerations section at B.3, access to Localhost services should be prevented while running in production.
The lookupWebFinger function, responsible for returning an actor handler for received actor objects from a remote server, can be abused to perform a Denial of Service (DoS) and Blind SSRF attacks while attempting to resolve a malicious actor’s object. On Fedify, two client-facing functions implement the lookupWebFinger function- getActorHandle, and lookupObject, which are both used as a wrapper for the vulnerable lookup function. As the lookupObject function is implemented only for CLI usage, we won’t focus our PoC and explanation on it, but it is still vulnerable in the same way getActorHandle is.
The getActorHandle function is a wrapper function for the getActorHandleInternal function (both present at /src/vocab/actor.ts):
async function getActorHandleInternal(
actor: Actor | URL,
options: GetActorHandleOptions = {},
): Promise<`@${string}@${string}` | `${string}@${string}`> {
const actorId = actor instanceof URL ? actor : actor.id;
if (actorId != null) {
const result = await lookupWebFinger(actorId, {
userAgent: options.userAgent,
tracerProvider: options.tracerProvider,
});
if (result != null) {
const aliases = [...(result.aliases ?? [])];
if (result.subject != null) aliases.unshift(result.subject);
for (const alias of aliases) {
const match = alias.match(/^acct:([^@]+)@([^@]+)$/);
if (match != null) {
const hostname = new URL(`https://${match[2]}/`).hostname;
if (
hostname !== actorId.hostname &&
!await verifyCrossOriginActorHandle(
actorId.href,
alias,
options.userAgent,
options.tracerProvider,
)
) {
continue;
}
return normalizeActorHandle(`@${match[1]}@${match[2]}`, options);
}
}
}
}
if (
!(actor instanceof URL) && actor.preferredUsername != null &&
actor.id != null
) {
return normalizeActorHandle(
`@${actor.preferredUsername}@${actor.id.host}`,
options,
);
}
throw new TypeError(
"Actor does not have enough information to get the handle.",
);
}
The actorId parameter containing a URL of the actor ID sinks into the lookupWebFinger function which is a wrapper for the lookupWebFingerInternal:
async function lookupWebFingerInternal(
resource: URL | string,
options: LookupWebFingerOptions = {},
): Promise<ResourceDescriptor | null> {
if (typeof resource === "string") resource = new URL(resource);
let protocol = "https:";
let server: string;
if (resource.protocol === "acct:") {
const atPos = resource.pathname.lastIndexOf("@");
if (atPos < 0) return null;
server = resource.pathname.substring(atPos + 1);
if (server === "") return null;
} else {
protocol = resource.protocol;
server = resource.host;
}
let url = new URL(`${protocol}//${server}/.well-known/webfinger`);
url.searchParams.set("resource", resource.href);
while (true) {
logger.debug(
"Fetching WebFinger resource descriptor from {url}...",
{ url: url.href },
);
let response: Response;
try {
response = await fetch(url, {
headers: {
Accept: "application/jrd+json",
"User-Agent": typeof options.userAgent === "string"
? options.userAgent
: getUserAgent(options.userAgent),
},
redirect: "manual",
});
} catch (error) {
logger.debug(
"Failed to fetch WebFinger resource descriptor: {error}",
{ url: url.href, error },
);
return null;
}
if (
response.status >= 300 && response.status < 400 &&
response.headers.has("Location")
) {
url = new URL(
response.headers.get("Location")!,
response.url == null || response.url === "" ? url : response.url,
);
continue;
}
if (!response.ok) {
logger.debug(
"Failed to fetch WebFinger resource descriptor: {status} {statusText}.",
{
url: url.href,
status: response.status,
statusText: response.statusText,
},
);
return null;
}
try {
return await response.json() as ResourceDescriptor;
} catch (e) {
if (e instanceof SyntaxError) {
logger.debug(
"Failed to parse WebFinger resource descriptor as JSON: {error}",
{ error: e },
);
return null;
}
throw e;
}
}
}
The function takes the actorId parameter containing the actor ID URL, extracts the scheme and uses the rest of the URL (host+port+path) directly inside a hard-coded Webfinger URL address which in turn sinks into a fetch request.
On the fetch request, the redirect attribute is set to “manual” preventing automated redirects. However, redirects are still handled using custom code that loops over responses and re-fetching the URL found inside the “Location” header until receiving a valid response or an error occurs (loop keeps until 300>status code>400).
This custom redirect implementation contains multiple issues: 1.The redirect loop is endless ( while(true) loop ) without any iteration limiting, allowing attackers to perform DoS via endless redirecting. 2. A Blind SSRF attack to any URL, with arbitrary Host, Port and Path is possible via the current custom redirect implementation. 3. As the redirect handler is a custom one, it breaches the security mechanisms presented by the native redirect handler of fetch - allowing the attacker to redirect to different schemes such as data or file schemes.
In order to successfully perform any of the attacks described above, an attacker needs to create a federated app which presents a malicious actor object, containing an actor ID URL of a second server which performs a recursive redirect to itself, or a URL containing an internal resource.
PoC
- In order to show a use case of the vulnerability, we can use the demo app presented at this URL: https://github.com/dahlia/microblog.
- We will create two machines, victim and attacker, each one on a different server with different domains.
Victim Machine
1. Create a new instance (we tested on ubuntu’s latest version), and update the package manager.
2. Install a Deno server:
curl -fsSL https://deno.land/install.sh | sh
source ~/.bashrc
deno --version #check deno is working
3. Pull the git repository of the victim blog app:
git clone https://github.com/dahlia/fedify.git
4. Modify the federation object to remove signature checks for the sake of easy testing:
On file /examples/blog/federation/mod.ts edit the createFederation object the following attribute: skipSignatureVerification: true.
5. Change into the blog app directory ( /examples/blog ) and run the app:
deno task preview
6. Surf to the application on the browser, and register a user on the app.
Attacker Machine
1. Create a new instance (we tested on ubuntu’s latest version), and update the package manager.
2. Install NVM in order to install the latest version of NPM and NODEJS (and source current shell to check it worked):
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
source ~/.bashrc
nvm list-remote
3. Install the latest stable version:
nvm install {latest_ver} #for example: v20.10.0
source ~/.bashrc
npm -v #check it works
node -v #check it works
4. Download the attacker app repository:
git clone https://github.com/dahlia/microblog.git
5. Disable request signature validations:
Edit the /src/federation.ts file and add a skipSignatureVerification: true attribute to the createFederation object.
6. Modify the /src/federation.ts file and tamper with the Person object on the actor dispatcher ( setActorDispatcher("/users/{identifier}" ) - change the actor ID attribute “id: ctx.getActorUri(identifier)” into “id: new URL(‘http://:1337/users/enterloop’)”.
7. Install python flask and create the Python Flask redirect server:
apt update
apt install python3-flask
from flask import Flask, redirect
app = Flask(__name__)
@app.route('/health')
def health():
return "hello", 200
@app.route('/.well-known/webfinger')
def ssrfinger():
return redirect("http://<ATTACKER_MACHINE_DOMAIN>:1337/endlessloop")
@app.route('/endlessloop')
def endlessloop():
return redirect("http://<ATTACKER_MACHINE_DOMAIN>:1337/endlessloop")
if __name__ == '__main__':
app.run(debug=True,host='0.0.0.0' ,port=1337)
- Run the python server and attempt to reach the “/health” path to see the server functions as expected.
- Read the README.txt file on the attacker app and follow the instructions on how to execute the app.
- Surf the app on the browser and attempt to follow the federated user on the victim’s machine.
- Send the “follow” request and watch the victim app continue to query the redirect server infinitely (It is possible to repeat this step multiple times causing multiple loops).
Impact
- Implement a limiting stop condition for the endless loop to prevent infinite loops.
- Validate the scheme while performing a manual redirection handler.
- For each web resource (for the lookupWebFinger function and also URLs found on the “Location” header inside the loop) use the “validatePublicUrl” function to verify that it is not targeting a local resource.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "@fedify/fedify"
},
"ranges": [
{
"events": [
{
"introduced": "1.0.13"
},
{
"fixed": "1.0.14"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.0.13"
]
},
{
"package": {
"ecosystem": "npm",
"name": "@fedify/fedify"
},
"ranges": [
{
"events": [
{
"introduced": "1.1.10"
},
{
"fixed": "1.1.11"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.1.10"
]
},
{
"package": {
"ecosystem": "npm",
"name": "@fedify/fedify"
},
"ranges": [
{
"events": [
{
"introduced": "1.2.10"
},
{
"fixed": "1.2.11"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.2.10"
]
},
{
"package": {
"ecosystem": "npm",
"name": "@fedify/fedify"
},
"ranges": [
{
"events": [
{
"introduced": "1.3.3"
},
{
"fixed": "1.3.4"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.3.3"
]
}
],
"aliases": [
"CVE-2025-23221"
],
"database_specific": {
"cwe_ids": [
"CWE-835",
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2025-01-21T19:58:29Z",
"nvd_published_at": "2025-01-20T17:15:07Z",
"severity": "MODERATE"
},
"details": "### Summary\nThis vulnerability allows a user to maneuver the Webfinger mechanism to perform a GET request to any internal resource on any Host, Port, URL combination regardless of present security mechanisms, and forcing the victim\u2019s server into an infinite loop causing Denial of Service.\nMoreover, this issue can also be maneuvered into performing a Blind SSRF attack.\n\n### Details\nThe Webfinger endpoint takes a remote domain for checking accounts as a feature, however, as per the ActivityPub spec (https://www.w3.org/TR/activitypub/#security-considerations), on the security considerations section at B.3, access to Localhost services should be prevented while running in production.\n\nThe **lookupWebFinger** function, responsible for returning an actor handler for received actor objects from a remote server, can be abused to perform a Denial of Service (DoS) and Blind SSRF attacks while attempting to resolve a malicious actor\u2019s object.\nOn Fedify, two client-facing functions implement the **lookupWebFinger** function- **getActorHandle**, and **lookupObject**, which are both used as a wrapper for the vulnerable lookup function.\nAs the **lookupObject** function is implemented only for CLI usage, we won\u2019t focus our PoC and explanation on it, but it is still vulnerable in the same way **getActorHandle** is.\n\nThe **getActorHandle** function is a wrapper function for the **getActorHandleInternal** function (both present at _/src/vocab/actor.ts_):\n```javascript\nasync function getActorHandleInternal(\n actor: Actor | URL,\n options: GetActorHandleOptions = {},\n): Promise\u003c`@${string}@${string}` | `${string}@${string}`\u003e {\n const actorId = actor instanceof URL ? actor : actor.id;\n if (actorId != null) {\n const result = await lookupWebFinger(actorId, {\n userAgent: options.userAgent,\n tracerProvider: options.tracerProvider,\n });\n if (result != null) {\n const aliases = [...(result.aliases ?? [])];\n if (result.subject != null) aliases.unshift(result.subject);\n for (const alias of aliases) {\n const match = alias.match(/^acct:([^@]+)@([^@]+)$/);\n if (match != null) {\n const hostname = new URL(`https://${match[2]}/`).hostname;\n if (\n hostname !== actorId.hostname \u0026\u0026\n !await verifyCrossOriginActorHandle(\n actorId.href,\n alias,\n options.userAgent,\n options.tracerProvider,\n )\n ) {\n continue;\n }\n return normalizeActorHandle(`@${match[1]}@${match[2]}`, options);\n }\n }\n }\n }\n if (\n !(actor instanceof URL) \u0026\u0026 actor.preferredUsername != null \u0026\u0026\n actor.id != null\n ) {\n return normalizeActorHandle(\n `@${actor.preferredUsername}@${actor.id.host}`,\n options,\n );\n }\n throw new TypeError(\n \"Actor does not have enough information to get the handle.\",\n );\n}\n```\n\nThe **actorId** parameter containing a URL of the actor ID sinks into the **lookupWebFinger** function which is a wrapper for the **lookupWebFingerInternal**:\n```javascript\nasync function lookupWebFingerInternal(\n resource: URL | string,\n options: LookupWebFingerOptions = {},\n): Promise\u003cResourceDescriptor | null\u003e {\n if (typeof resource === \"string\") resource = new URL(resource);\n let protocol = \"https:\";\n let server: string;\n if (resource.protocol === \"acct:\") {\n const atPos = resource.pathname.lastIndexOf(\"@\");\n if (atPos \u003c 0) return null;\n server = resource.pathname.substring(atPos + 1);\n if (server === \"\") return null;\n } else {\n protocol = resource.protocol;\n server = resource.host;\n }\n let url = new URL(`${protocol}//${server}/.well-known/webfinger`);\n url.searchParams.set(\"resource\", resource.href);\n while (true) {\n logger.debug(\n \"Fetching WebFinger resource descriptor from {url}...\",\n { url: url.href },\n );\n let response: Response;\n try {\n response = await fetch(url, {\n headers: {\n Accept: \"application/jrd+json\",\n \"User-Agent\": typeof options.userAgent === \"string\"\n ? options.userAgent\n : getUserAgent(options.userAgent),\n },\n redirect: \"manual\",\n });\n } catch (error) {\n logger.debug(\n \"Failed to fetch WebFinger resource descriptor: {error}\",\n { url: url.href, error },\n );\n return null;\n }\n if (\n response.status \u003e= 300 \u0026\u0026 response.status \u003c 400 \u0026\u0026\n response.headers.has(\"Location\")\n ) {\n url = new URL(\n response.headers.get(\"Location\")!,\n response.url == null || response.url === \"\" ? url : response.url,\n );\n continue;\n }\n if (!response.ok) {\n logger.debug(\n \"Failed to fetch WebFinger resource descriptor: {status} {statusText}.\",\n {\n url: url.href,\n status: response.status,\n statusText: response.statusText,\n },\n );\n return null;\n }\n try {\n return await response.json() as ResourceDescriptor;\n } catch (e) {\n if (e instanceof SyntaxError) {\n logger.debug(\n \"Failed to parse WebFinger resource descriptor as JSON: {error}\",\n { error: e },\n );\n return null;\n }\n throw e;\n }\n }\n}\n```\n\nThe function takes the **actorId** parameter containing the actor ID URL, extracts the scheme and uses the rest of the URL (host+port+path) directly inside a hard-coded Webfinger URL address which in turn sinks into a fetch request.\n\nOn the fetch request, the **redirect** attribute is set to \u201c**manual**\u201d preventing automated redirects. However, redirects are still handled using custom code that loops over responses and re-fetching the URL found inside the \u201cLocation\u201d header until receiving a valid response or an error occurs (loop keeps until 300\u003estatus code\u003e400).\n\nThis custom redirect implementation contains multiple issues:\n1.The redirect loop is endless ( while(true) loop ) without any iteration limiting, allowing attackers to perform DoS via endless redirecting.\n2. A Blind SSRF attack to any URL, with arbitrary Host, Port and Path is possible via the current custom redirect implementation.\n3. As the redirect handler is a custom one, it breaches the security mechanisms presented by the native redirect handler of fetch - allowing the attacker to redirect to different schemes such as data or file schemes.\n\nIn order to successfully perform any of the attacks described above, an attacker needs to create a federated app which presents a malicious actor object, containing an actor ID URL of a second server which performs a recursive redirect to itself, or a URL containing an internal resource.\n\n\n### PoC\n1. In order to show a use case of the vulnerability, we can use the demo app presented at this URL: https://github.com/dahlia/microblog.\n2. We will create two machines, victim and attacker, each one on a different server with different domains.\n\n**_Victim Machine_**\n1. Create a new instance (we tested on ubuntu\u2019s latest version), and update the package manager.\n2. Install a Deno server:\n`\ncurl -fsSL https://deno.land/install.sh | sh\n`\n`\nsource ~/.bashrc\n`\n`\ndeno --version #check deno is working\n`\n3. Pull the git repository of the victim blog app:\n`\ngit clone https://github.com/dahlia/fedify.git\n`\n4. Modify the federation object to remove signature checks for the sake of easy testing:\nOn file **_/examples/blog/federation/mod.ts_** edit the **_createFederation\u003cvoid\u003e_** object the following attribute: **_skipSignatureVerification: true_**.\n5. Change into the blog app directory ( /examples/blog ) and run the app:\n`\ndeno task preview\n`\n6. Surf to the application on the browser, and register a user on the app.\n\n**_Attacker Machine_**\n1. Create a new instance (we tested on ubuntu\u2019s latest version), and update the package manager.\n2. Install NVM in order to install the latest version of NPM and NODEJS (and source current shell to check it worked):\n`\ncurl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash\n`\n`\nsource ~/.bashrc\n`\n`\nnvm list-remote\n`\n3. Install the latest stable version:\n`\nnvm install {latest_ver} #for example: v20.10.0\n`\n`\nsource ~/.bashrc\n`\n`\nnpm -v #check it works\n`\n`\nnode -v #check it works\n`\n4. Download the attacker app repository:\n`\ngit clone https://github.com/dahlia/microblog.git\n`\n5. Disable request signature validations:\nEdit the **_/src/federation.ts_** file and add a **_skipSignatureVerification: true_** attribute to the **_createFederation_** object.\n6. Modify the **_/src/federation.ts_** file and tamper with the Person object on the actor dispatcher ( **_setActorDispatcher(\"/users/{identifier}\"_** ) - change the actor ID attribute **_\u201cid: ctx.getActorUri(identifier)_**\u201d into \u201c**_id: new URL(\u2018http://\u003cATTACKER_MACHINE_DOMAIN\u003e:1337/users/enterloop\u2019)_**\u201d.\n7. Install python flask and create the Python Flask redirect server:\n`\napt update\n`\n`\napt install python3-flask\n`\n```python\nfrom flask import Flask, redirect\n\napp = Flask(__name__)\n\n@app.route(\u0027/health\u0027)\ndef health():\n return \"hello\", 200\n\n@app.route(\u0027/.well-known/webfinger\u0027)\ndef ssrfinger():\n return redirect(\"http://\u003cATTACKER_MACHINE_DOMAIN\u003e:1337/endlessloop\")\n\n@app.route(\u0027/endlessloop\u0027)\ndef endlessloop():\n return redirect(\"http://\u003cATTACKER_MACHINE_DOMAIN\u003e:1337/endlessloop\")\n\nif __name__ == \u0027__main__\u0027:\n app.run(debug=True,host=\u00270.0.0.0\u0027 ,port=1337)\n```\n8. Run the python server and attempt to reach the \u201c**_/health_**\u201d path to see the server functions as expected.\n9. Read the **_README.txt_** file on the attacker app and follow the instructions on how to execute the app.\n10. Surf the app on the browser and attempt to follow the federated user on the victim\u2019s machine.\n11. Send the \u201cfollow\u201d request and watch the victim app continue to query the redirect server infinitely (It is possible to repeat this step multiple times causing multiple loops).\n\n\n### Impact\n1. Implement a limiting stop condition for the endless loop to prevent infinite loops.\n2. Validate the scheme while performing a manual redirection handler.\n3. For each web resource (for the **_lookupWebFinger_** function and also URLs found on the \u201c**_Location_**\u201d header inside the loop) use the \u201c**_validatePublicUrl_**\u201d function to verify that it is not targeting a local resource.\n",
"id": "GHSA-c59p-wq67-24wx",
"modified": "2025-01-21T19:58:29Z",
"published": "2025-01-21T19:58:29Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/dahlia/fedify/security/advisories/GHSA-c59p-wq67-24wx"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-23221"
},
{
"type": "WEB",
"url": "https://github.com/dahlia/fedify/commit/8be3c2038eebf4ae12481683a1e809b314be3151"
},
{
"type": "WEB",
"url": "https://github.com/dahlia/fedify/commit/c505eb82fcd6b5b17174c6659c29721bc801ab9a"
},
{
"type": "WEB",
"url": "https://github.com/dahlia/fedify/commit/e921134dd5097586e4563ea80b9e8d1b5460a645"
},
{
"type": "PACKAGE",
"url": "https://github.com/dahlia/fedify"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L",
"type": "CVSS_V3"
}
],
"summary": "Infinite loop and Blind SSRF found inside the Webfinger mechanism in @fedify/fedify"
}
GHSA-C873-F884-8R22
Vulnerability from github – Published: 2022-05-13 01:44 – Updated: 2022-05-13 01:44An issue was discovered in QPDF before 7.0.0. There is an infinite loop in the QPDFWriter::enqueueObject() function in libqpdf/QPDFWriter.cc.
{
"affected": [],
"aliases": [
"CVE-2017-18183"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-02-13T19:29:00Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in QPDF before 7.0.0. There is an infinite loop in the QPDFWriter::enqueueObject() function in libqpdf/QPDFWriter.cc.",
"id": "GHSA-c873-f884-8r22",
"modified": "2022-05-13T01:44:36Z",
"published": "2022-05-13T01:44:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-18183"
},
{
"type": "WEB",
"url": "https://github.com/qpdf/qpdf/issues/143"
},
{
"type": "WEB",
"url": "https://github.com/qpdf/qpdf/commit/8249a26d69f72b9cda584c14cc3f12769985e481"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/3638-1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-C87F-HW9Q-6V9P
Vulnerability from github – Published: 2022-05-13 01:53 – Updated: 2022-05-13 01:53In Wireshark 2.4.0 to 2.4.4 and 2.2.0 to 2.2.12, epan/dissectors/packet-dcm.c had an infinite loop that was addressed by checking for integer wraparound.
{
"affected": [],
"aliases": [
"CVE-2018-7322"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-02-23T22:29:00Z",
"severity": "HIGH"
},
"details": "In Wireshark 2.4.0 to 2.4.4 and 2.2.0 to 2.2.12, epan/dissectors/packet-dcm.c had an infinite loop that was addressed by checking for integer wraparound.",
"id": "GHSA-c87f-hw9q-6v9p",
"modified": "2022-05-13T01:53:19Z",
"published": "2022-05-13T01:53:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-7322"
},
{
"type": "WEB",
"url": "https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=14411"
},
{
"type": "WEB",
"url": "https://code.wireshark.org/review/gitweb?p=wireshark.git;a=commit;h=afc780e2c796e971bb7d164103f4f0d10d3c25b5"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2018/04/msg00018.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2019/01/msg00010.html"
},
{
"type": "WEB",
"url": "https://www.wireshark.org/security/wnpa-sec-2018-06.html"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/103158"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-C8Q7-3FQ2-CVVG
Vulnerability from github – Published: 2022-05-13 01:24 – Updated: 2025-04-20 03:33The make_available_at_least function in io-tiff.c in gdk-pixbuf allows context-dependent attackers to cause a denial of service (infinite loop) via a large TIFF file.
{
"affected": [],
"aliases": [
"CVE-2017-6314"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-03-10T02:59:00Z",
"severity": "MODERATE"
},
"details": "The make_available_at_least function in io-tiff.c in gdk-pixbuf allows context-dependent attackers to cause a denial of service (infinite loop) via a large TIFF file.",
"id": "GHSA-c8q7-3fq2-cvvg",
"modified": "2025-04-20T03:33:57Z",
"published": "2022-05-13T01:24:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-6314"
},
{
"type": "WEB",
"url": "https://bugzilla.gnome.org/show_bug.cgi?id=779020"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2019/12/msg00025.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SJF5ARFOX4BFUK6YCBKGAKBQYECO3AI2"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VSAZ6UCKKXC5VOWXGWQHOX2ZBLLATIOT"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SJF5ARFOX4BFUK6YCBKGAKBQYECO3AI2"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VSAZ6UCKKXC5VOWXGWQHOX2ZBLLATIOT"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/201709-08"
},
{
"type": "WEB",
"url": "http://mov.sx/2017/02/21/bug-hunting-gdk-pixbuf.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2017/02/21/4"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2017/02/26/1"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/96779"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-C8RR-9GXC-JPRV
Vulnerability from github – Published: 2026-03-18 13:01 – Updated: 2026-03-20 21:19Summary
ujson.dumps() crashes the Python interpreter (segmentation fault) when the product of the indent parameter and the nested depth of the input exceeds INT32_MAX. It can also get stuck in an infinite loop if the indent is a large negative number. Both are caused by an integer overflow/underflow whilst calculating how much memory to reserve for indentation. And both can be used to achieve denial of service.
(Note: A negative indent to ujson means add spaces after colons but do not add line breaks or indentation. It is unclear to the current maintainers whether this was ever even an intended feature or just a byproduct of the way it was written.)
Exploitability
To be vulnerable, a service must call ujson.dump()/ujson.dumps()/ujson.encode() whilst giving untrusted users control over the indent parameter and not restrict that indentation to reasonably small non-negative values. (Even with the fix for this vulnerability, such usage is strongly advised against since even a bug-free JSON serialiser would be vulnerable to denial of service simply by the attacker requesting indents that have the server needlessly filling out gigabytes of whitespace.)
A service may also be vulnerable to the infinite loop if it uses a fixed negative indent. An underflow always occurs for any negative indent when the input data is at least one level nested but, for small negative indents, the underflow is usually accidentally rectified by another overflow. As far as the maintainers are aware, the infinite loop can not be reached for indentations from -1 to -65536 / max_recursion_depth_as_limited_by_stack_size but users of negative indents are encouraged to consider their service affected even if the infinite loop seems unreachable.
Example
import ujson
def example(depth, indent):
a = [0]
for i in range(1000):
a = [a]
ujson.dumps(a, indent=indent)
example(1, 2**30) # segfault
example(1000, -200) # infinite loop
Patches
ujson 5.12.0, containing 486bd4553dc471a1de11613bc7347a6b318e37ea, promotes the integer types where the overflow occurred, skips the indentation code path for negative indent (which was supposed to be a no-op) and places an artificial cap of 1000 on the indent parameter.
Workarounds
Users who don't wish to upgrade can either use a fixed indentation, no indentation or ensure indentation is non-negative and not enormous (below 2**31 / max_recursion_depth_as_limited_by_stack_size).
References
The original bug report can be found at https://github.com/ultrajson/ultrajson/issues/700
This issue was independently discovered by @coco1629, @EthanKim88 and @vmfunc.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.11.0"
},
"package": {
"ecosystem": "PyPI",
"name": "ujson"
},
"ranges": [
{
"events": [
{
"introduced": "5.1.0"
},
{
"fixed": "5.12.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-32875"
],
"database_specific": {
"cwe_ids": [
"CWE-190",
"CWE-787",
"CWE-835"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-18T13:01:24Z",
"nvd_published_at": "2026-03-20T02:16:35Z",
"severity": "HIGH"
},
"details": "### Summary\n\n`ujson.dumps()` crashes the Python interpreter (segmentation fault) when the product of the `indent` parameter and the nested depth of the input exceeds INT32_MAX. It can also get stuck in an infinite loop if the `indent` is a large negative number. Both are caused by an integer overflow/underflow whilst calculating how much memory to reserve for indentation. And both can be used to achieve denial of service.\n\n(Note: A negative indent to `ujson` means add spaces after colons but do not add line breaks or indentation. It is unclear to the current maintainers whether this was ever even an intended feature or just a byproduct of the way it was written.)\n\n### Exploitability\n\nTo be vulnerable, a service must call `ujson.dump()`/`ujson.dumps()`/`ujson.encode()` whilst giving untrusted users control over the `indent` parameter and not restrict that indentation to reasonably small non-negative values. (Even with the fix for this vulnerability, such usage is strongly advised against since even a bug-free JSON serialiser would be vulnerable to denial of service simply by the attacker requesting indents that have the server needlessly filling out gigabytes of whitespace.)\n\nA service may also be vulnerable to the infinite loop if it uses a fixed _negative_ `indent`. An underflow always occurs for any negative indent when the input data is at least one level nested but, for small negative indents, the underflow is usually accidentally rectified by another overflow. As far as the maintainers are aware, the infinite loop can not be reached for indentations from -1 to -65536 / max_recursion_depth_as_limited_by_stack_size but users of negative indents are encouraged to consider their service affected even if the infinite loop seems unreachable.\n\n### Example\n\n```python\nimport ujson\n\ndef example(depth, indent):\n a = [0]\n for i in range(1000):\n a = [a]\n ujson.dumps(a, indent=indent)\n\nexample(1, 2**30) # segfault\nexample(1000, -200) # infinite loop\n```\n\n### Patches\n\nujson 5.12.0, containing 486bd4553dc471a1de11613bc7347a6b318e37ea, promotes the integer types where the overflow occurred, skips the indentation code path for negative indent (which was supposed to be a no-op) and places an artificial cap of 1000 on the `indent` parameter.\n\n### Workarounds\n\nUsers who don\u0027t wish to upgrade can either use a fixed indentation, no indentation or ensure indentation is non-negative and not enormous (below `2**31 / max_recursion_depth_as_limited_by_stack_size`).\n\n### References\n\nThe original bug report can be found at https://github.com/ultrajson/ultrajson/issues/700\n\nThis issue was independently discovered by @coco1629, @EthanKim88 and @vmfunc.",
"id": "GHSA-c8rr-9gxc-jprv",
"modified": "2026-03-20T21:19:56Z",
"published": "2026-03-18T13:01:24Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c8rr-9gxc-jprv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32875"
},
{
"type": "WEB",
"url": "https://github.com/ultrajson/ultrajson/issues/700"
},
{
"type": "WEB",
"url": "https://github.com/ultrajson/ultrajson/commit/486bd4553dc471a1de11613bc7347a6b318e37ea"
},
{
"type": "PACKAGE",
"url": "https://github.com/ultrajson/ultrajson"
}
],
"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": "UltraJSON has an integer overflow handling large indent leads to buffer overflow or infinite loop"
}
GHSA-C93F-9F7G-FV7H
Vulnerability from github – Published: 2022-05-13 01:19 – Updated: 2022-05-13 01:19libhttp/url.c in shellinabox through 2.20 has an implementation flaw in the HTTP request parsing logic. By sending a crafted multipart/form-data HTTP request, an attacker could exploit this to force shellinaboxd into an infinite loop, exhausting available CPU resources and taking the service down.
{
"affected": [],
"aliases": [
"CVE-2018-16789"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-03-21T16:00:00Z",
"severity": "HIGH"
},
"details": "libhttp/url.c in shellinabox through 2.20 has an implementation flaw in the HTTP request parsing logic. By sending a crafted multipart/form-data HTTP request, an attacker could exploit this to force shellinaboxd into an infinite loop, exhausting available CPU resources and taking the service down.",
"id": "GHSA-c93f-9f7g-fv7h",
"modified": "2022-05-13T01:19:17Z",
"published": "2022-05-13T01:19:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-16789"
},
{
"type": "WEB",
"url": "https://github.com/shellinabox/shellinabox/commit/4f0ecc31ac6f985e0dd3f5a52cbfc0e9251f6361"
},
{
"type": "WEB",
"url": "https://code.google.com/archive/p/shellinabox/issues"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/149978/Shell-In-A-Box-2.2.0-Denial-Of-Service.html"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2018/Oct/50"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-C9H4-M6H9-V7WX
Vulnerability from github – Published: 2022-05-24 19:08 – Updated: 2022-10-16 19:00Crash in DNP dissector in Wireshark 3.4.0 to 3.4.6 and 3.2.0 to 3.2.14 allows denial of service via packet injection or crafted capture file
{
"affected": [],
"aliases": [
"CVE-2021-22235"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-07-20T12:15:00Z",
"severity": "HIGH"
},
"details": "Crash in DNP dissector in Wireshark 3.4.0 to 3.4.6 and 3.2.0 to 3.2.14 allows denial of service via packet injection or crafted capture file",
"id": "GHSA-c9h4-m6h9-v7wx",
"modified": "2022-10-16T19:00:30Z",
"published": "2022-05-24T19:08:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-22235"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22235.json"
},
{
"type": "WEB",
"url": "https://gitlab.com/wireshark/wireshark/-/issues/17462"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202210-04"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2021/dsa-5019"
},
{
"type": "WEB",
"url": "https://www.wireshark.org/security/wnpa-sec-2021-05.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:H",
"type": "CVSS_V3"
}
]
}
No mitigation information available for this CWE.
No CAPEC attack patterns related to this CWE.