An inverted boolean parameter resulted in TLB flushes not happening upon clearing of a present translation table entry. Retaining stale TLB entries could allow guests access to memory that ought to have
been revoked, or grant greater access than intended.
Malicious guest administrators might be able to cause host-wide denial of service, or escalate their privilege to that of the host.
References:
http://seclists.org/oss-sec/2013/q4/322
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 as we did not have support for Xen hypervisor.