DSA-2544-1 xen -- denial of service

Related Vulnerabilities: CVE-2012-3494   CVE-2012-3496  

Multiple denial of service vulnerabilities have been discovered in Xen, an hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2012-3494: It was discovered that set_debugreg allows writes to reserved bits of the DR7 debug control register on amd64 (x86-64) paravirtualised guests, allowing a guest to crash the host. CVE-2012-3496: Matthew Daley discovered that XENMEM_populate_physmap, when called with the MEMF_populate_on_demand flag set, a BUG (detection routine) can be triggered if a translating paging mode is not being used, allowing a guest to crash the host. For the stable distribution (squeeze), these problems have been fixed in version 4.0.1-5.4. For the testing distribution (wheezy), these problems will be fixed soon. For the unstable distribution (sid), these problems have been fixed in version 4.1.3-2. We recommend that you upgrade your xen packages.

Debian Security Advisory

DSA-2544-1 xen -- denial of service

Date Reported:
08 Sep 2012
Affected Packages:
xen
Vulnerable:
Yes
Security database references:
In Mitre's CVE dictionary: CVE-2012-3494, CVE-2012-3496.
More information:

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

  • CVE-2012-3494:

    It was discovered that set_debugreg allows writes to reserved bits of the DR7 debug control register on amd64 (x86-64) paravirtualised guests, allowing a guest to crash the host.

  • CVE-2012-3496:

    Matthew Daley discovered that XENMEM_populate_physmap, when called with the MEMF_populate_on_demand flag set, a BUG (detection routine) can be triggered if a translating paging mode is not being used, allowing a guest to crash the host.

For the stable distribution (squeeze), these problems have been fixed in version 4.0.1-5.4.

For the testing distribution (wheezy), these problems will be fixed soon.

For the unstable distribution (sid), these problems have been fixed in version 4.1.3-2.

We recommend that you upgrade your xen packages.