CVE-2015-7837

El kernel de Linux, tal y como se emplea en Red Hat Enterprise Linux 7, kernel-rt y Enterprise MRG 2 y cuando se emplea con UEFI Secure Boot habilitado, permite que usuarios locales omitan las restricciones securelevel/secureboot previstas aprovechando la gestión incorrecta de la marca secure_boot cuando se reinicia kexec.

A flaw was found in the way the Linux kernel handled the securelevel functionality after performing a kexec operation. A local attacker could use this flaw to bypass the security mechanism of the securelevel/secureboot combination.

The kernel-rt packages contain the Linux kernel, the core of any Linux operating system. A flaw was found in the way the Linux kernel's file system implementation handled rename operations in which the source was inside and the destination was outside of a bind mount. A privileged user inside a container could use this flaw to escape the bind mount and, potentially, escalate their privileges on the system. A race condition flaw was found in the way the Linux kernel's IPC subsystem initialized certain fields in an IPC object structure that were later used for permission checking before inserting the object into a globally visible list. A local, unprivileged user could potentially use this flaw to elevate their privileges on the system.