xen - several

Multiple vulnerabilities have been discovered in the Xen hypervisor. The
Common Vulnerabilities and Exposures project identifies the following
problems:

• CVE-2013-1918

(XSA
45) several long latency operations are not preemptible.

Some page table manipulation operations for PV guests were not made
preemptible, allowing a malicious or buggy PV guest kernel to mount a
denial of service attack affecting the whole system.

• CVE-2013-1952

(XSA
49) VT-d interrupt remapping source validation flaw for bridges.

Due to missing source validation on interrupt remapping table
entries for MSI interrupts set up by bridge devices, a malicious
domain with access to such a device can mount a denial of service
attack affecting the whole system.

• CVE-2013-1964

(XSA
50) grant table hypercall acquire/release imbalance.

When releasing a particular, non-transitive grant after doing a grant
copy operation, Xen incorrectly releases an unrelated grant
reference, leading possibly to a crash of the host system.
Furthermore information leakage or privilege escalation cannot be
ruled out.

For the oldstable distribution (squeeze), these problems have been fixed in
version 4.0.1-5.11.

For the stable distribution (wheezy), these problems have been fixed in
version 4.1.4-3+deb7u1.

For the testing distribution (jessie), these problems have been fixed in
version 4.1.4-4.

For the unstable distribution (sid), these problems have been fixed in
version 4.1.4-4.

Note that for the stable (wheezy), testing and unstable distribution,
CVE-2013-1964
(XSA
50) was already fixed in version 4.1.4-3.

We recommend that you upgrade your xen packages.