CVE-2025-61771

Full vulnerability record from the local CVENow database.

Description

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.

Severity

HIGH

CVSS score

7.5 (v3.1)

Vulnerability status

Analyzed

Source identifier

[email protected]

Published

2025-10-07 15:16:03.123000

Last modified

2026-10-19 16:10:00.260000

View original CVE JSON

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  "id": "CVE-2025-61771",
  "sourceIdentifier": "[email protected]",
  "published": "2025-10-07T15:16:03.123",
  "lastModified": "2026-10-19T16:10:00.260",
  "vulnStatus": "Analyzed",
  "cveTags": [],
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      "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."
    },
    {
      "lang": "es",
      "value": "Rack es una interfaz modular de servidor web Ruby. En versiones anteriores a la 2.2.19, 3.1.17 y 3.2.2, 'Rack::Multipart::Parser' almacena campos de formulario que no son archivos (partes sin un 'filename') completamente en memoria como objetos Ruby 'String'. Un único campo de texto grande en una solicitud multipart/form-data (cientos de megabytes o más) puede consumir memoria de proceso equivalente, lo que podría llevar a condiciones de falta de memoria (OOM) y denegación de servicio (DoS). Los atacantes pueden enviar campos grandes que no son archivos para desencadenar un uso excesivo de memoria. El impacto escala con el tamaño de la solicitud y la concurrencia, lo que podría llevar a fallos de los workers o a una sobrecarga severa de la recolección de basura. Todas las aplicaciones Rack que procesan envíos de formularios multipart están afectadas. Las versiones 2.2.19, 3.1.17 y 3.2.2 imponen un límite de tamaño razonable para los campos que no son archivos (p. ej., 2 MiB). Las soluciones incluyen restringir el tamaño máximo del cuerpo de la solicitud en la capa del servidor web o proxy (p. ej., Nginx 'client_max_body_size') y validar y rechazar campos de formulario inusualmente grandes a nivel de aplicación."
    }
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          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
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      "type": "Secondary",
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}