CVE-2025-39917

Estado: ModificadaAlta (7.8)—

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt

Stanislav reported that in bpf_crypto_crypt() the destination dynptr's size is not validated to be at least as large as the source dynptr's size before calling into the crypto backend with 'len = src_len'. This can result in an OOB write when the destination is smaller than the source.

Concretely, in mentioned function, psrc and pdst are both linear buffers fetched from each dynptr:

The crypto backend expects pdst to be large enough with a src_len length that can be written. Add an additional src_len > dst_len check and bail out if it's the case. Note that these kfuncs are accessible under root privileges only.

Detalles técnicos trazas, registros y código del informe original

  psrc = __bpf_dynptr_data(src, src_len);
  [...]
  pdst = __bpf_dynptr_data_rw(dst, dst_len);
  [...]
  err = decrypt ?
        ctx->type->decrypt(ctx->tfm, psrc, pdst, src_len, piv) :
        ctx->type->encrypt(ctx->tfm, psrc, pdst, src_len, piv);

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.15%
Percentil entre todas las CVEs puntuadas: 4
Fecha de la puntuación: 6/10/2026

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1059 Command and Scripting Interpreterexecution75 %
Impacto secundarioT1565.001 Stored Data Manipulationimpact70 %

Vulnerabilidad de escritura fuera de límites (CWE-787) en kernel de Linux con acceso local (AV:L) sin interacción (UI:N) que permite escalada de privilegios. El defecto en bpf_crypto_crypt() puede ejecutar código con privilegios elevados (T1059) y corromper datos del sistema (T1565.001).

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 Prevention Threat Intelligence Program Restrict Web-Based Content Restrict File and Directory Permissions Privileged Account Management Remote Data Storage

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-787
CWE-787

Referencias

JSON original (NVD)

Mostrar

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