CVE-2025-67726

Gravedad CVSS v3.1:

ALTA

Tipo:

CWE-400 Consumo de recursos no controlado (Agotamiento de recursos)

Fecha de publicación:

12/12/2025

Última modificación:

22/12/2025

Descripción

*** Pendiente de traducción *** Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server&#39;s CPU usage increases quadratically (O(n²)) during parsing. Due to Tornado&#39;s single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3.

Impacto

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severidad y Métricas:

Puntuación base: 7.50 ALTA
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vector de acceso (AV): A través de red
Complejidad de acceso (AC): Bajo
Privilegios Requeridos (PR): Ninguno
Interacción del usuario (UI): Ninguno
Alcance (S): Sin modificar
Impacto a la confidencialidad (C): Ninguno
Impacto a la integridad (I): Ninguno
Impacto a la disponibilidad (A): Alto