CVE-2021-3715

Se ha encontrado un fallo en el clasificador "Routing decision" del subsistema de red Traffic Control del kernel de Linux en la forma en que administra el cambio de los filtros de clasificación, conllevando a una condición de uso de memoria previamente liberada. Este fallo permite a usuarios locales no privilegiados escalar sus privilegios en el sistema. La mayor amenaza de esta vulnerabilidad es para la confidencialidad, la integridad y la disponibilidad del sistema

Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). De4dCr0w of 360 Alpha Lab discovered that the BPF verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker could use this to expose sensitive information (kernel memory) or possibly execute arbitrary code. Various other vulnerabilities were also addressed.