CVE-2012-0055

OverlayFS en el kernel de Linux versiones anteriores a 3.0.0-16.28, como es usado en Ubuntu versiones 10.0.4 LTS y 11.10, carece de verificaciones de seguridad de inode que podrían permitir a atacantes omitir las restricciones de seguridad y llevar a cabo acciones no autorizadas.

A flaw was found in KVM's Programmable Interval Timer (PIT). When a virtual interrupt control is not available a local user could use this to cause a denial of service by starting a timer. A flaw was discovered in the XFS filesystem. If a local user mounts a specially crafted XFS image it could potential execute arbitrary code on the system. Andy Whitcroft discovered a that the Overlayfs filesystem was not doing the extended permission checks needed by cgroups and Linux Security Modules (LSMs). A local user could exploit this to by-pass security policy and access files that should not be accessible. Various other issues were also addressed.