FKIE_CVE-2025-61771

Vulnerability from fkie_nvd - Published: 2025-10-07 15:16 - Updated: 2026-06-17 09:50
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, ``Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level.
References
security-advisories@github.comhttps://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181ePatch
security-advisories@github.comhttps://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29ePatch
security-advisories@github.comhttps://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fdPatch
security-advisories@github.comhttps://github.com/rack/rack/security/advisories/GHSA-w9pc-fmgc-vxvwVendor Advisory
Impacted products
Vendor Product Version
rack rack *
rack rack *
rack rack *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "rack",
          "vendor": "rack",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.2.19"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.1, \u003c 3.1.17"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.2, \u003c 3.2.2"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "EBB6060B-A06F-4A88-8457-AD850E63E562",
              "versionEndExcluding": "2.2.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "850EC79C-0F31-441F-9001-B7CA0CD7758F",
              "versionEndExcluding": "3.1.17",
              "versionStartIncluding": "3.1.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "9A009CC5-8010-446E-A12B-BF5314CA5BEB",
              "versionEndExcluding": "3.2.2",
              "versionStartIncluding": "3.2.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, ``Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level."
    }
  ],
  "id": "CVE-2025-61771",
  "lastModified": "2026-06-17T09:50:52.380",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-61771",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-10-07T17:51:58.348077Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-10-07T15:16:03.123",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/rack/rack/commit/589127f4ac8b5cf11cf88fb0cd116ffed4d2181e"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/rack/rack/commit/d869fed663b113b95a74ad53e1b5cae6ab31f29e"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/rack/rack/commit/e08f78c656c9394d6737c022bde087e0f33336fd"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/rack/rack/security/advisories/GHSA-w9pc-fmgc-vxvw"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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