Vulnerabilidad · Publicado 19/08/2026
Una falla en los comandos GETALL y SETALL de semctl(2) permite que atacantes locales manipulen semáforos del kernel entre ciclos de creación/destrucción, explotando un desbordamiento de secuencia tras 0x8000 operaciones. Afecta sistemas Unix/Linux en producción que ejecutan aplicaciones multi-proceso con semáforos del sistema operativo, comprometiendo la integridad de sincronización en bases de datos y middleware alta.
The GETALL and SETALL commands in semctl(2) recorded the number of semaphores in the target set, dropped the lock protecting the set, allocated a buffer sized for that count, and reacquired the lock. A sequence-number check was used to verify that the set had not been replaced in the interim, but the sequence number wraps after 0x8000 create/destroy cycles. By rapidly destroying and recreating semaphore sets at the same index, another process can cause the sequence number to wrap, allowing a set with a different number of semaphores to pass validation. The subsequent copy then reads or writes past the end of the allocated buffer. An unprivileged local user can trigger out-of-bounds reads and writes on kernel heap memory, potentially leading to privilege escalation.
Score: 7.8/10 — Severidad: HIGH — Estado NIST: Received
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE-125, CWE-191, CWE-787
Publicado en NIST NVD.