The FLASK_AVC_CACHESTAT hypercall, which provides access to per-cpu statistics on the Flask security policy, incorrectly validates the CPU for which statistics are being requested.
An attacker can cause the hypervisor to read past the end of an array. This may result in either a host crash, leading to a denial of service, or access to a small and static region of hypervisor memory, leading to an information leak.
External reference:
http://seclists.org/oss-sec/2014/q1/263
Acknowledgements:
Red Hat would like to thank the Xen project for reporting this issue.
Statement:
Not vulnerable.
This issue did not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5.
This issue did not affect Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG 2 as we did not have support for Xen hypervisor.