Common Weakness Enumeration

CWE-770

Allowed

Allocation of Resources Without Limits or Throttling

Abstraction: Base · Status: Incomplete

API response cwe.mitre.org

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.

3026 vulnerabilities reference this CWE, most recent first.

GHSA-F4JQ-8GQC-63V2

Vulnerability from github – Published: 2025-02-13 00:33 – Updated: 2025-02-14 18:30
VLAI
Details

An issue in the profile image upload function of LearnDash v6.7.1 allows attackers to cause a Denial of Service (DoS) via excessive file uploads.

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-2024-56940"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400",
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-12T22:15:40Z",
    "severity": "HIGH"
  },
  "details": "An issue in the profile image upload function of LearnDash v6.7.1 allows attackers to cause a Denial of Service (DoS) via excessive file uploads.",
  "id": "GHSA-f4jq-8gqc-63v2",
  "modified": "2025-02-14T18:30:49Z",
  "published": "2025-02-13T00:33:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-56940"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nikolas-ch/CVEs/tree/main/LearnDash_v6.7.1"
    }
  ],
  "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-F5V4-2WR6-HQMG

Vulnerability from github – Published: 2026-04-24 15:39 – Updated: 2026-05-13 13:34
VLAI
Summary
russh has pre-auth DoS via unbounded allocation in its keyboard-interactive auth handler
Details

Summary

A pre-authentication denial-of-service vulnerability exists in the server's keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials.

Vulnerability Details

In russh/src/server/encrypted.rs, the function read_userauth_info_response decodes a u32 count from the client's SSH_MSG_USERAUTH_INFO_RESPONSE and passes it directly to Vec::with_capacity():

let n = map_err!(u32::decode(r))?;

// Bound both allocation and iteration by remaining packet data to
// prevent a malicious client from causing a multi-GB allocation or
// billions of loop iterations with a crafted count.
// Each response needs at least 4 bytes (length prefix).
let max_responses = r.remaining_len().saturating_add(3) / 4;
let n = (n as usize).min(max_responses);
let mut responses = Vec::with_capacity(n);
for _ in 0..n {
    responses.push(Bytes::decode(r).ok())
}

An attacker can send n = 0x10000000 (268M) or larger in a minimal packet (~50 bytes after encryption). The server attempts to allocate n * ~24 bytes (size of Option<Bytes>) = ~6.4GB, causing an OOM crash.

Attack Flow

  1. Attacker connects via TCP, completes key exchange (no credentials needed -- this is the anonymous DH handshake, not authentication)
  2. Sends USERAUTH_REQUEST with method keyboard-interactive
  3. Server handler returns Auth::Partial with prompts (standard for 2FA/TOTP)
  4. Attacker sends USERAUTH_INFO_RESPONSE with n = 0x10000000 and no response data
  5. Server calls Vec::with_capacity(268_435_456), OOM killed

No authentication is required. The allocation occurs before the handler validates any credentials. The attack is repeatable faster than the server can restart.

Affected Configurations

Any russh-based server where the Handler::auth_keyboard_interactive implementation returns Auth::Partial (i.e., sends prompts to the client). The default handler returns Auth::reject() and is not affected.

Source code review suggests that downstream projects using keyboard-interactive for multi-step auth (e.g., TOTP/2FA) follow the affected pattern, since returning Auth::Partial before credential verification is the intended API usage for prompting.

Confirmed End-to-End PoC

There is a complete Docker-contained PoC confirming the OOM kill: - Minimal russh server returning Auth::Partial for keyboard-interactive - Python client (paramiko for key exchange) sends malformed USERAUTH_INFO_RESPONSE - Container with 512MB memory limit; server is OOM-killed (exit code 137)

Available on request.

Proposed Fix

Cap the Vec::with_capacity allocation to what the remaining packet data can actually contain. Each response requires at least 4 bytes (length prefix), so:

let n = map_err!(u32::decode(r))?;

// Bound both allocation and iteration by remaining packet data to
// prevent a malicious client from causing a multi-GB allocation or
// billions of loop iterations with a crafted count.
// Each response needs at least 4 bytes (length prefix).
let max_responses = r.remaining_len().saturating_add(3) / 4;
let n = (n as usize).min(max_responses);
let mut responses = Vec::with_capacity(n);
for _ in 0..n {
    responses.push(Bytes::decode(r).ok())
}

This bounds the allocation to at most the packet size (~256KB), while preserving the existing behavior for well-formed packets. This fix has been implemented, tested, and contributed via the temporary private fork.

Severity

Pre-auth, remote, no credentials required, crashes the server process affecting all active sessions.

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": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "russh"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.60.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42189"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770",
      "CWE-789"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-24T15:39:37Z",
    "nvd_published_at": "2026-05-08T20:16:31Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nA pre-authentication denial-of-service vulnerability exists in the server\u0027s keyboard-interactive authentication handler. A malicious client can crash any russh-based server that implements keyboard-interactive auth (e.g., for 2FA/TOTP) with a single malformed packet, requiring no credentials.\n\n## Vulnerability Details\n\nIn `russh/src/server/encrypted.rs`, the function `read_userauth_info_response` decodes a `u32` count from the client\u0027s `SSH_MSG_USERAUTH_INFO_RESPONSE` and passes it directly to `Vec::with_capacity()`:\n\n```rust\nlet n = map_err!(u32::decode(r))?;\n\n// Bound both allocation and iteration by remaining packet data to\n// prevent a malicious client from causing a multi-GB allocation or\n// billions of loop iterations with a crafted count.\n// Each response needs at least 4 bytes (length prefix).\nlet max_responses = r.remaining_len().saturating_add(3) / 4;\nlet n = (n as usize).min(max_responses);\nlet mut responses = Vec::with_capacity(n);\nfor _ in 0..n {\n    responses.push(Bytes::decode(r).ok())\n}\n```\n\nAn attacker can send `n = 0x10000000` (268M) or larger in a minimal packet (~50 bytes after encryption). The server attempts to allocate `n * ~24 bytes` (size of `Option\u003cBytes\u003e`) = ~6.4GB, causing an OOM crash.\n\n## Attack Flow\n\n1. Attacker connects via TCP, completes key exchange (no credentials needed -- this is the anonymous DH handshake, not authentication)\n2. Sends `USERAUTH_REQUEST` with method `keyboard-interactive`\n3. Server handler returns `Auth::Partial` with prompts (standard for 2FA/TOTP)\n4. Attacker sends `USERAUTH_INFO_RESPONSE` with `n = 0x10000000` and no response data\n5. Server calls `Vec::with_capacity(268_435_456)`, OOM killed\n\nNo authentication is required. The allocation occurs before the handler validates any credentials. The attack is repeatable faster than the server can restart.\n\n## Affected Configurations\n\nAny russh-based server where the `Handler::auth_keyboard_interactive` implementation returns `Auth::Partial` (i.e., sends prompts to the client). The default handler returns `Auth::reject()` and is not affected.\n\nSource code review suggests that downstream projects using keyboard-interactive for multi-step auth (e.g., TOTP/2FA) follow the affected pattern, since returning `Auth::Partial` before credential verification is the intended API usage for prompting.\n\n## Confirmed End-to-End PoC\n\nThere is a complete Docker-contained PoC confirming the OOM kill:\n- Minimal russh server returning `Auth::Partial` for keyboard-interactive\n- Python client (paramiko for key exchange) sends malformed `USERAUTH_INFO_RESPONSE`\n- Container with 512MB memory limit; server is OOM-killed (exit code 137)\n\nAvailable on request.\n\n## Proposed Fix\n\nCap the `Vec::with_capacity` allocation to what the remaining packet data can actually contain. Each response requires at least 4 bytes (length prefix), so:\n\n```rust\nlet n = map_err!(u32::decode(r))?;\n\n// Bound both allocation and iteration by remaining packet data to\n// prevent a malicious client from causing a multi-GB allocation or\n// billions of loop iterations with a crafted count.\n// Each response needs at least 4 bytes (length prefix).\nlet max_responses = r.remaining_len().saturating_add(3) / 4;\nlet n = (n as usize).min(max_responses);\nlet mut responses = Vec::with_capacity(n);\nfor _ in 0..n {\n    responses.push(Bytes::decode(r).ok())\n}\n```\n\nThis bounds the allocation to at most the packet size (~256KB), while preserving the existing behavior for well-formed packets. This fix has been implemented, tested, and contributed via the temporary private fork.\n\n## Severity\n\nPre-auth, remote, no credentials required, crashes the server process affecting all active sessions.",
  "id": "GHSA-f5v4-2wr6-hqmg",
  "modified": "2026-05-13T13:34:53Z",
  "published": "2026-04-24T15:39:37Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-f5v4-2wr6-hqmg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42189"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Eugeny/russh/commit/6c3c80a9b6d60763d6227d60fa8310e57172a4d1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Eugeny/russh"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Eugeny/russh/releases/tag/v0.60.1"
    }
  ],
  "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": "russh has pre-auth DoS via unbounded allocation in its keyboard-interactive auth handler"
}

GHSA-F5V8-V6Q3-Q4H6

Vulnerability from github – Published: 2026-04-16 22:50 – Updated: 2026-04-16 22:50
VLAI
Summary
Meridian: Multiple defense-in-depth gaps (collection/depth caps, telemetry, retry, fan-out)
Details

Summary

Meridian v2.1.0 (Meridian.Mapping and Meridian.Mediator) shipped with nine defense-in-depth gaps reachable through its public APIs. Two are HIGH severity — the advertised DefaultMaxCollectionItems and DefaultMaxDepth safety caps are silently bypassed on the IMapper.Map(source, destination) overload and anywhere .UseDestinationValue() is configured on a collection-typed property. Four are MEDIUM (constructor invariant bypass, OpenTelemetry stack-trace info disclosure, retry amplification, notification fan-out amplification). Three are LOW (exception message disclosure, dictionary duplicate-key echo, static mediator cache growth under closed-generic types).

All nine are patched in v2.1.1. Upgrade is a drop-in NuGet bump; see the v2.1.1 CHANGELOG for the four behavioural changes (constructor selection, OTel default, publisher fan-out cap, retry caps).

Severity Matrix

# Severity CWE Finding Fix
1 HIGH CWE-770 MappingEngine.TryMapCollectionOntoExisting enumerated the source without enforcing DefaultMaxCollectionItems. Reachable via Mapper.Map<TSrc,TDst>(src, dst) and any .ForMember(..., o => o.UseDestinationValue()) on a collection member through a plain Map(src) call. Shared cap enforcement helper between MapCollection and TryMapCollectionOntoExisting.
2 HIGH CWE-674 Collection-item recursion in the existing-destination path did not increment ResolutionContext.Depth, so self-referential collection graphs could reach stack overflow before DefaultMaxDepth fired. Depth increments at every collection-item boundary.
3 MEDIUM CWE-665 ObjectCreator.CreateWithConstructorMapping always invoked the widest public constructor, silently filling unresolved parameters with default(T) and bypassing narrower-ctor invariants. Widest-ctor selection now requires every parameter to be bound via explicit ctor mapping, source-name match, or a C# optional default.
4 MEDIUM CWE-532 Mediator.MarkActivityFailure emitted the full ex.ToString() (stack + inner chain) to the OpenTelemetry exception.stacktrace activity tag by default, leaking context to any shared trace sink. Gated on MediatorTelemetryOptions.RecordExceptionStackTrace — opt-in, default false.
5 MEDIUM CWE-400 RetryBehavior retried every exception type with unbounded MaxRetries; the exponential-backoff delay overflowed TimeSpan at ~30 attempts. No cancellation exclusion. Server-side MaxRetriesCap = 10, MaxBackoff = 5 min, OperationCanceledException short-circuit, recommended RetryPolicy.TransientOnly helper.
6 MEDIUM CWE-400 TaskWhenAllPublisher started every registered handler concurrently with no bound on fan-out. New constructor parameter maxDegreeOfParallelism (default 16; -1 restores legacy unbounded).
7 LOW CWE-209 Public mapping exceptions leaked FullName of source/destination types and concatenated inner exception messages into top-level property-mapping errors. Scrubbed to type Name; inner details only via InnerException chain.
8 LOW CWE-209 Dictionary materialization threw ArgumentException on duplicate keys, echoing the attacker-supplied key's .ToString(). Last-write-wins indexer semantics.
9 LOW CWE-1325 Static mediator handler caches grow monotonically under closed-generic request types. Doc-only mitigation; no code change — consumers must not allow attacker-controlled runtime type materialization to reach Send, Publish, or CreateStream. Documented in docs/security-model.md.

Exploitation

Finding 1 / 2 (headline): A consumer that maps user-supplied collection payloads onto an existing destination list via mapper.Map(userCollection, existingList) — a documented and commonly used AutoMapper-style idiom — processes the full attacker-supplied collection with no size cap and no depth cap. An attacker sending a single request with a large (or self-referential) collection payload can block the worker thread for seconds and exhaust the managed heap or the call stack. Equivalent exposure through .UseDestinationValue() on a collection-typed destination member, reachable via a plain Map(src) call whose destination type default-initializes that member.

Finding 3: A destination type with multiple public constructors that differ only in their parameter-binding invariants (e.g., new UserAccount(string name, Email email) enforcing a non-default Email) could be instantiated with the narrower ctor's invariants silently bypassed if any source field was absent — the widest ctor was always picked, with unbound parameters replaced by default(T).

Findings 4 / 5 / 6: Amplification / information-disclosure vectors described in the matrix above. Each requires moderate integration context (telemetry sink trust, handler count, retry policy) to weaponize, but each is reachable through public APIs without authentication.

Patches

  • Meridian.Mapping 2.1.1 (published 2026-04-16)
  • Meridian.Mediator 2.1.1 (published 2026-04-16)

Verified via: - GitHub Release assets at https://github.com/UmutKorkmaz/meridian/releases/tag/v2.1.1 - Sigstore attestation (actions/attest-build-provenance@v2 → gh attestation verify green on both .nupkg from the GitHub Release) - NuGet.org indexed both packages within the release workflow run

Workarounds

Users who cannot upgrade immediately may: 1. Avoid mapper.Map(src, dst) and .UseDestinationValue() on collection-typed destination members. 2. Wrap input collection deserialization with an explicit size limit before handing the payload to Meridian. 3. Register TaskWhenAllPublisher with maxDegreeOfParallelism ≤ 16 manually (v2.1.1+ only). 4. Disable OpenTelemetry exception.stacktrace tag emission at the trace exporter level if your trace sink is less trusted than your application.

These are defense-in-depth; the only complete mitigation is upgrading to 2.1.1.

Supported Versions

As of this advisory the supported security branch is 2.1.x. The 2.0.x line (published 2026-04-15) is not receiving the Phase 1 safety-defaults infrastructure needed to carry the HIGH-severity fixes, so 2.0.x is deprecated in favor of 2.1.x. See SECURITY.md for the updated supported-versions table.

Credits

  • UmutKorkmaz (reporter and maintainer)

References

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": [
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Meridian.Mapping"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "NuGet",
        "name": "Meridian.Mediator"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-1325",
      "CWE-209",
      "CWE-400",
      "CWE-532",
      "CWE-665",
      "CWE-674",
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-16T22:50:37Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\n\nMeridian v2.1.0 (`Meridian.Mapping` and `Meridian.Mediator`) shipped with nine defense-in-depth gaps reachable through its public APIs. Two are HIGH severity \u2014 the advertised `DefaultMaxCollectionItems` and `DefaultMaxDepth` safety caps are silently bypassed on the `IMapper.Map(source, destination)` overload and anywhere `.UseDestinationValue()` is configured on a collection-typed property. Four are MEDIUM (constructor invariant bypass, OpenTelemetry stack-trace info disclosure, retry amplification, notification fan-out amplification). Three are LOW (exception message disclosure, dictionary duplicate-key echo, static mediator cache growth under closed-generic types).\n\nAll nine are patched in **v2.1.1**. Upgrade is a drop-in NuGet bump; see the v2.1.1 CHANGELOG for the four behavioural changes (constructor selection, OTel default, publisher fan-out cap, retry caps).\n\n## Severity Matrix\n\n| # | Severity | CWE | Finding | Fix |\n|---|---|---|---|---|\n| 1 | **HIGH** | CWE-770 | `MappingEngine.TryMapCollectionOntoExisting` enumerated the source without enforcing `DefaultMaxCollectionItems`. Reachable via `Mapper.Map\u003cTSrc,TDst\u003e(src, dst)` and any `.ForMember(..., o =\u003e o.UseDestinationValue())` on a collection member through a plain `Map(src)` call. | Shared cap enforcement helper between `MapCollection` and `TryMapCollectionOntoExisting`. |\n| 2 | **HIGH** | CWE-674 | Collection-item recursion in the existing-destination path did not increment `ResolutionContext.Depth`, so self-referential collection graphs could reach stack overflow before `DefaultMaxDepth` fired. | Depth increments at every collection-item boundary. |\n| 3 | MEDIUM | CWE-665 | `ObjectCreator.CreateWithConstructorMapping` always invoked the widest public constructor, silently filling unresolved parameters with `default(T)` and bypassing narrower-ctor invariants. | Widest-ctor selection now requires every parameter to be bound via explicit ctor mapping, source-name match, or a C# optional default. |\n| 4 | MEDIUM | CWE-532 | `Mediator.MarkActivityFailure` emitted the full `ex.ToString()` (stack + inner chain) to the OpenTelemetry `exception.stacktrace` activity tag by default, leaking context to any shared trace sink. | Gated on `MediatorTelemetryOptions.RecordExceptionStackTrace` \u2014 opt-in, default `false`. |\n| 5 | MEDIUM | CWE-400 | `RetryBehavior` retried every exception type with unbounded `MaxRetries`; the exponential-backoff delay overflowed `TimeSpan` at ~30 attempts. No cancellation exclusion. | Server-side `MaxRetriesCap = 10`, `MaxBackoff = 5 min`, `OperationCanceledException` short-circuit, recommended `RetryPolicy.TransientOnly` helper. |\n| 6 | MEDIUM | CWE-400 | `TaskWhenAllPublisher` started every registered handler concurrently with no bound on fan-out. | New constructor parameter `maxDegreeOfParallelism` (default 16; `-1` restores legacy unbounded). |\n| 7 | LOW | CWE-209 | Public mapping exceptions leaked `FullName` of source/destination types and concatenated inner exception messages into top-level property-mapping errors. | Scrubbed to type `Name`; inner details only via `InnerException` chain. |\n| 8 | LOW | CWE-209 | Dictionary materialization threw `ArgumentException` on duplicate keys, echoing the attacker-supplied key\u0027s `.ToString()`. | Last-write-wins indexer semantics. |\n| 9 | LOW | CWE-1325 | Static mediator handler caches grow monotonically under closed-generic request types. **Doc-only mitigation**; no code change \u2014 consumers must not allow attacker-controlled runtime type materialization to reach `Send`, `Publish`, or `CreateStream`. | Documented in `docs/security-model.md`. |\n\n## Exploitation\n\n**Finding 1 / 2 (headline):** A consumer that maps user-supplied collection payloads onto an existing destination list via `mapper.Map(userCollection, existingList)` \u2014 a documented and commonly used AutoMapper-style idiom \u2014 processes the full attacker-supplied collection with no size cap and no depth cap. An attacker sending a single request with a large (or self-referential) collection payload can block the worker thread for seconds and exhaust the managed heap or the call stack. Equivalent exposure through `.UseDestinationValue()` on a collection-typed destination member, reachable via a plain `Map(src)` call whose destination type default-initializes that member.\n\n**Finding 3:** A destination type with multiple public constructors that differ only in their parameter-binding invariants (e.g., `new UserAccount(string name, Email email)` enforcing a non-default `Email`) could be instantiated with the narrower ctor\u0027s invariants silently bypassed if any source field was absent \u2014 the widest ctor was always picked, with unbound parameters replaced by `default(T)`.\n\n**Findings 4 / 5 / 6:** Amplification / information-disclosure vectors described in the matrix above. Each requires moderate integration context (telemetry sink trust, handler count, retry policy) to weaponize, but each is reachable through public APIs without authentication.\n\n## Patches\n\n- `Meridian.Mapping` **2.1.1** (published 2026-04-16)\n- `Meridian.Mediator` **2.1.1** (published 2026-04-16)\n\nVerified via:\n- GitHub Release assets at \u003chttps://github.com/UmutKorkmaz/meridian/releases/tag/v2.1.1\u003e\n- Sigstore attestation (`actions/attest-build-provenance@v2` \u2192 `gh attestation verify` green on both `.nupkg` from the GitHub Release)\n- NuGet.org indexed both packages within the release workflow run\n\n## Workarounds\n\nUsers who cannot upgrade immediately may:\n1. Avoid `mapper.Map(src, dst)` and `.UseDestinationValue()` on collection-typed destination members.\n2. Wrap input collection deserialization with an explicit size limit before handing the payload to Meridian.\n3. Register `TaskWhenAllPublisher` with `maxDegreeOfParallelism` \u2264 16 manually (v2.1.1+ only).\n4. Disable OpenTelemetry `exception.stacktrace` tag emission at the trace exporter level if your trace sink is less trusted than your application.\n\nThese are defense-in-depth; the only complete mitigation is upgrading to 2.1.1.\n\n## Supported Versions\n\nAs of this advisory the supported security branch is **2.1.x**. The 2.0.x line (published 2026-04-15) is not receiving the Phase 1 safety-defaults infrastructure needed to carry the HIGH-severity fixes, so 2.0.x is deprecated in favor of 2.1.x. See `SECURITY.md` for the updated supported-versions table.\n\n## Credits\n\n- UmutKorkmaz (reporter and maintainer)\n\n## References\n\n- v2.1.1 CHANGELOG section: \u003chttps://github.com/UmutKorkmaz/meridian/blob/main/CHANGELOG.md#211---2026-04-16\u003e\n- `docs/security-model.md` threat model: \u003chttps://github.com/UmutKorkmaz/meridian/blob/main/docs/security-model.md\u003e\n- `SECURITY.md` disclosure policy: \u003chttps://github.com/UmutKorkmaz/meridian/blob/main/SECURITY.md\u003e\n- AutoMapper CVE-2026-32933 (motivating precedent for Meridian\u0027s safety-defaults)",
  "id": "GHSA-f5v8-v6q3-q4h6",
  "modified": "2026-04-16T22:50:37Z",
  "published": "2026-04-16T22:50:37Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/UmutKorkmaz/meridian/security/advisories/GHSA-f5v8-v6q3-q4h6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/UmutKorkmaz/meridian"
    },
    {
      "type": "WEB",
      "url": "https://github.com/UmutKorkmaz/meridian/blob/main/CHANGELOG.md#211---2026-04-16"
    },
    {
      "type": "WEB",
      "url": "https://github.com/UmutKorkmaz/meridian/releases/tag/v2.1.1"
    }
  ],
  "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": "Meridian: Multiple defense-in-depth gaps (collection/depth caps, telemetry, retry, fan-out)"
}

GHSA-F5VP-W269-392G

Vulnerability from github – Published: 2026-07-06 21:10 – Updated: 2026-07-07 22:17
VLAI
Summary
Coder vulnerable to denial of service via unbounded request body in AI Bridge provider endpoints
Details

Summary

AI Bridge provider handlers read request bodies with io.ReadAll without a maximum size so an authenticated user with AI Bridge access could send an arbitrarily large body and exhaust memory.

Note: Exploitation requires authenticated access to the AI Bridge endpoints and the impact is limited to availability (denial of service).

Impact

An authenticated member-level user could POST a very large or chunked body to an AI Bridge provider endpoint such as /api/v2/aibridge/anthropic/v1/messages, growing heap memory until the operating system terminates the process. Because AI Bridge runs in-process with coderd, this crashes the entire control plane, including the API, workspace coordinator and DERP relay. It requires an authenticated user and the AI Bridge feature enabled.

Patches

The fix applies http.MaxBytesReader or an equivalent cap before reading provider and session request bodies. The affected AI Bridge provider endpoints exist only on the v2.33 and v2.34 lines. Earlier release lines are not affected.

The fix is available in the following releases:

Release line Patched version
2.34 v2.34.2
2.33 v2.33.8

Workarounds

None.

Resources

  • Fix: #26164

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22443) for independently disclosing this issue!

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coder/coder/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.34.0"
            },
            {
              "fixed": "2.34.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/coder/coder/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.33.0"
            },
            {
              "fixed": "2.33.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55434"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-06T21:10:13Z",
    "nvd_published_at": "2026-07-07T21:17:27Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nAI Bridge provider handlers read request bodies with `io.ReadAll` without a maximum size so an authenticated user with AI Bridge access could send an arbitrarily large body and exhaust memory.\n\n\u003e **Note:** Exploitation requires authenticated access to the AI Bridge endpoints and the impact is limited to availability (denial of service).\n\n### Impact\n\nAn authenticated member-level user could POST a very large or chunked body to an AI Bridge provider endpoint such as `/api/v2/aibridge/anthropic/v1/messages`, growing heap memory until the operating system terminates the process. Because AI Bridge runs in-process with `coderd`, this crashes the entire control plane, including the API, workspace coordinator and DERP relay. It requires an authenticated user and the AI Bridge feature enabled.\n\n### Patches\n\nThe fix applies `http.MaxBytesReader` or an equivalent cap before reading provider and session request bodies. The affected AI Bridge provider endpoints exist only on the v2.33 and v2.34 lines. Earlier release lines are not affected.\n\nThe fix is available in the following releases:\n\n| Release line | Patched version |\n|---|---|\n| 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) |\n| 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) |\n\n### Workarounds\n\nNone.\n\n### Resources\n\n- Fix: #26164\n\n### Credits\n\nCoder would like to thank Anthropic\u0027s Security Team (ANT-2026-22443) for independently disclosing this issue!",
  "id": "GHSA-f5vp-w269-392g",
  "modified": "2026-07-07T22:17:48Z",
  "published": "2026-07-06T21:10:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/security/advisories/GHSA-f5vp-w269-392g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55434"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/pull/26164"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/coder/coder"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/releases/tag/v2.33.8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/coder/coder/releases/tag/v2.34.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Coder vulnerable to denial of service via unbounded request body in AI Bridge provider endpoints"
}

GHSA-F637-JPFQ-3WV2

Vulnerability from github – Published: 2022-05-24 17:34 – Updated: 2022-05-24 17:34
VLAI
Details

A flaw was found in the way the spice-vdagentd daemon handled file transfers from the host system to the virtual machine. Any unprivileged local guest user with access to the UNIX domain socket path /run/spice-vdagentd/spice-vdagent-sock could use this flaw to perform a memory denial of service for spice-vdagentd or even other processes in the VM system. The highest threat from this vulnerability is to system availability. This flaw affects spice-vdagent versions 0.20 and previous versions.

Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2020-25650"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2020-11-25T15:15:00Z",
    "severity": "MODERATE"
  },
  "details": "A flaw was found in the way the spice-vdagentd daemon handled file transfers from the host system to the virtual machine. Any unprivileged local guest user with access to the UNIX domain socket path `/run/spice-vdagentd/spice-vdagent-sock` could use this flaw to perform a memory denial of service for spice-vdagentd or even other processes in the VM system. The highest threat from this vulnerability is to system availability. This flaw affects spice-vdagent versions 0.20 and previous versions.",
  "id": "GHSA-f637-jpfq-3wv2",
  "modified": "2022-05-24T17:34:56Z",
  "published": "2022-05-24T17:34:56Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-25650"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1886345"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2021/01/msg00012.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GQT56LATVTB2DJOVVJOKQVMVUXYCT2VB"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OIWJ2EIQXWEA2VDBODEATHAT37X4CREP"
    },
    {
      "type": "WEB",
      "url": "https://www.openwall.com/lists/oss-security/2020/11/04/1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-F67M-8H88-QHQH

Vulnerability from github – Published: 2026-01-08 18:30 – Updated: 2026-06-30 03:35
VLAI
Details

An issue in Technitium DNS Server v.13.5 allows a remote attacker to cause a denial of service via the rate-limiting component

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
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{
  "affected": [],
  "aliases": [
    "CVE-2025-50334"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-08T17:15:47Z",
    "severity": "HIGH"
  },
  "details": "An issue in Technitium DNS Server v.13.5 allows a remote attacker to cause a denial of service via the rate-limiting component",
  "id": "GHSA-f67m-8h88-qhqh",
  "modified": "2026-06-30T03:35:24Z",
  "published": "2026-01-08T18:30:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-50334"
    },
    {
      "type": "WEB",
      "url": "https://github.com/TechnitiumSoftware/DnsServer/commit/7229b217238213cc6275eea68a7e17d73df1603e"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2025-50334"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2428058"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FPokerFace/Security-Advisory/tree/main/CVE-2025-50334"
    },
    {
      "type": "WEB",
      "url": "https://github.com/TechnitiumSoftware/DnsServer/blob/master/CHANGELOG.md"
    },
    {
      "type": "WEB",
      "url": "https://github.com/TechnitiumSoftware/DnsServer/blob/v13.3/DnsServerCore/Dns/DnsServer.cs"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-50334.json"
    },
    {
      "type": "WEB",
      "url": "http://technitium.com"
    }
  ],
  "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-F699-HCHG-47FV

Vulnerability from github – Published: 2022-05-13 01:46 – Updated: 2022-05-13 01:46
VLAI
Details

A vulnerability in Cisco Prime Data Center Network Manager (DCNM) Software could allow an unauthenticated, remote attacker to log in to the administrative console of a DCNM server by using an account that has a default, static password. The account could be granted root- or system-level privileges. The vulnerability exists because the affected software has a default user account that has a default, static password. The user account is created automatically when the software is installed. An attacker could exploit this vulnerability by connecting remotely to an affected system and logging in to the affected software by using the credentials for this default user account. A successful exploit could allow the attacker to use this default user account to log in to the affected software and gain access to the administrative console of a DCNM server. This vulnerability affects Cisco Prime Data Center Network Manager (DCNM) Software releases prior to Release 10.2(1) for Microsoft Windows, Linux, and Virtual Appliance platforms. Cisco Bug IDs: CSCvd95346.

Severity
9.8 (Critical)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2017-6640"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2017-06-08T13:29:00Z",
    "severity": "CRITICAL"
  },
  "details": "A vulnerability in Cisco Prime Data Center Network Manager (DCNM) Software could allow an unauthenticated, remote attacker to log in to the administrative console of a DCNM server by using an account that has a default, static password. The account could be granted root- or system-level privileges. The vulnerability exists because the affected software has a default user account that has a default, static password. The user account is created automatically when the software is installed. An attacker could exploit this vulnerability by connecting remotely to an affected system and logging in to the affected software by using the credentials for this default user account. A successful exploit could allow the attacker to use this default user account to log in to the affected software and gain access to the administrative console of a DCNM server. This vulnerability affects Cisco Prime Data Center Network Manager (DCNM) Software releases prior to Release 10.2(1) for Microsoft Windows, Linux, and Virtual Appliance platforms. Cisco Bug IDs: CSCvd95346.",
  "id": "GHSA-f699-hchg-47fv",
  "modified": "2022-05-13T01:46:43Z",
  "published": "2022-05-13T01:46:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2017-6640"
    },
    {
      "type": "WEB",
      "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170607-dcnm2"
    },
    {
      "type": "WEB",
      "url": "http://www.securityfocus.com/bid/98937"
    },
    {
      "type": "WEB",
      "url": "http://www.securitytracker.com/id/1038625"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-F6F8-9MX6-9MX2

Vulnerability from github – Published: 2024-07-10 06:33 – Updated: 2025-11-04 19:48
VLAI
Summary
Django vulnerable to Denial of Service
Details

An issue was discovered in Django 5.0 before 5.0.7 and 4.2 before 4.2.14. get_supported_language_variant() was subject to a potential denial-of-service attack when used with very long strings containing specific characters.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Django"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0"
            },
            {
              "fixed": "5.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Django"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2"
            },
            {
              "fixed": "4.2.14"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-39614"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-130",
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-07-10T21:43:25Z",
    "nvd_published_at": "2024-07-10T05:15:12Z",
    "severity": "HIGH"
  },
  "details": "An issue was discovered in Django 5.0 before 5.0.7 and 4.2 before 4.2.14. `get_supported_language_variant()` was subject to a potential denial-of-service attack when used with very long strings containing specific characters.",
  "id": "GHSA-f6f8-9mx6-9mx2",
  "modified": "2025-11-04T19:48:05Z",
  "published": "2024-07-10T06:33:52Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-39614"
    },
    {
      "type": "WEB",
      "url": "https://github.com/django/django/commit/17358fb35fb7217423d4c4877ccb6d1a3a40b1c3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/django/django/commit/8e7a44e4bec0f11474699c3111a5e0a45afe7f49"
    },
    {
      "type": "WEB",
      "url": "https://docs.djangoproject.com/en/dev/releases/security"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/django/django"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/django/PYSEC-2024-59.yaml"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/forum/#%21forum/django-announce"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20240808-0005"
    },
    {
      "type": "WEB",
      "url": "https://www.djangoproject.com/weblog/2024/jul/09/security-releases"
    }
  ],
  "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"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Django vulnerable to Denial of Service"
}

GHSA-F6JC-WWHW-GPQ7

Vulnerability from github – Published: 2022-05-24 19:06 – Updated: 2022-05-24 19:06
VLAI
Details

The Sieve engine in Dovecot before 2.3.15 allows Uncontrolled Resource Consumption, as demonstrated by a situation with a complex regular expression for the regex extension.

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

{
  "affected": [],
  "aliases": [
    "CVE-2020-28200"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-697",
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-06-28T13:15:00Z",
    "severity": "MODERATE"
  },
  "details": "The Sieve engine in Dovecot before 2.3.15 allows Uncontrolled Resource Consumption, as demonstrated by a situation with a complex regular expression for the regex extension.",
  "id": "GHSA-f6jc-wwhw-gpq7",
  "modified": "2022-05-24T19:06:26Z",
  "published": "2022-05-24T19:06:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-28200"
    },
    {
      "type": "WEB",
      "url": "https://dovecot.org/security"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JB2VTJ3G2ILYWH5Y2FTY2PUHT2MD6VMI"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TK424DWFO2TKJYXZ2H3XL633TYJL4GQN"
    },
    {
      "type": "WEB",
      "url": "https://www.openwall.com/lists/oss-security/2021/06/28/3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-F725-67X4-3V5H

Vulnerability from github – Published: 2025-01-28 00:32 – Updated: 2025-11-03 21:32
VLAI
Details

The issue was addressed with improved checks. This issue is fixed in iPadOS 17.7.4, macOS Ventura 13.7.3, macOS Sonoma 14.7.3, visionOS 2.3, iOS 18.3 and iPadOS 18.3, macOS Sequoia 15.3, watchOS 11.3, tvOS 18.3. Parsing a file may lead to an unexpected app termination.

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

{
  "affected": [],
  "aliases": [
    "CVE-2025-24124"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-01-27T22:15:17Z",
    "severity": "CRITICAL"
  },
  "details": "The issue was addressed with improved checks. This issue is fixed in iPadOS 17.7.4, macOS Ventura 13.7.3, macOS Sonoma 14.7.3, visionOS 2.3, iOS 18.3 and iPadOS 18.3, macOS Sequoia 15.3, watchOS 11.3, tvOS 18.3. Parsing a file may lead to an unexpected app termination.",
  "id": "GHSA-f725-67x4-3v5h",
  "modified": "2025-11-03T21:32:25Z",
  "published": "2025-01-28T00:32:14Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-24124"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122066"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122067"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122068"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122069"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122070"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122071"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122072"
    },
    {
      "type": "WEB",
      "url": "https://support.apple.com/en-us/122073"
    },
    {
      "type": "WEB",
      "url": "http://seclists.org/fulldisclosure/2025/Jan/12"
    },
    {
      "type": "WEB",
      "url": "http://seclists.org/fulldisclosure/2025/Jan/14"
    },
    {
      "type": "WEB",
      "url": "http://seclists.org/fulldisclosure/2025/Jan/15"
    },
    {
      "type": "WEB",
      "url": "http://seclists.org/fulldisclosure/2025/Jan/16"
    },
    {
      "type": "WEB",
      "url": "http://seclists.org/fulldisclosure/2025/Jan/17"
    },
    {
      "type": "WEB",
      "url": "http://seclists.org/fulldisclosure/2025/Jan/19"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}
Mitigation
Requirements

Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.

Mitigation
Architecture and Design

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
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, 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
Implementation

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
Architecture and Design

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
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 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
Architecture and Design

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

Mitigation MIT-38.1
Architecture and Design Implementation
  • 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
Operation Architecture and Design

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.

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