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CVE-2025-62495

Estado: AnalizadaAlta (7.1)—

An integer overflow vulnerability exists in the QuickJS regular expression engine (libregexp) due to an inconsistent representation of the bytecode buffer size.

Detalles técnicos trazas, registros y código del informe original
  *  The regular expression bytecode is stored in a DynBuf structure, which correctly uses a $\text{size}\_\text{t}$ (an unsigned type, typically 64-bit) for its size member.

  *  However, several functions, such as re_emit_op_u32 and other internal parsing routines, incorrectly cast or store this DynBuf $\text{size}\_\text{t}$ value into a signed int (typically 32-bit).

  *  When a large or complex regular expression (such as those generated by a recursive pattern in a Proof-of-Concept) causes the bytecode size to exceed $2^{31}$ bytes (the maximum positive value for a signed 32-bit integer), the size value wraps around, resulting in a negative integer when stored in the int variable (Integer Overflow).

  *  This negative value is subsequently used in offset calculations. For example, within functions like re_parse_disjunction, the negative size is used to compute an offset (pos) for patching a jump instruction.

  *  This negative offset is then incorrectly added to the buffer pointer (s->byte\_code.buf + pos), leading to an out-of-bounds write on the first line of the snippet below:

put_u32(s->byte_code.buf + pos, len);

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

UI:P y PR:L indican interacción del usuario y acceso local (T1203). La vulnerabilidad de desbordamiento de enteros en regex puede permitir ejecución de código (T1059) y potencialmente escalar privilegios (T1068) mediante escritura fuera de límites.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Execution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate SoftwareThreat Intelligence ProgramRestrict Web-Based Content

Tecnologías afectadas (1)

Quickjs Project — Quickjs

CWE

Referencias

JSON original (NVD)

Mostrar
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  "lastModified": "2026-06-17T09:51:59.020",
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