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Debian Security Advisory DSA-2501-1                   security@debian.org
http://www.debian.org/security/                            Florian Weimer
June 24, 2012                          http://www.debian.org/security/faq
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Package        : xen
Vulnerability  : several
Problem type   : local
Debian-specific: no
CVE ID         : CVE-2012-0217 CVE-2012-0218 CVE-2012-2934

Several vulnerabilities were discovered in Xen, a hypervisor.

CVE-2012-0217
	Xen does not properly handle uncanonical return addresses on
	Intel amd64 CPUs, allowing amd64 PV guests to elevate to
	hypervisor privileges.  AMD processors, HVM and i386 guests
	are not affected.

CVE-2012-0218
	Xen does not properly handle SYSCALL and SYSENTER instructions
	in PV guests, allowing unprivileged users inside a guest
	system to crash the guest system.

CVE-2012-2934
	Xen does not detect old AMD CPUs affected by AMD Erratum #121.

For CVE-2012-2934, Xen refuses to start domUs on affected systems
unless the "allow_unsafe" option is passed.

For the stable distribution (squeeze), these problems have been fixed
in version 4.0.1-5.2.

For the testing distribution (wheezy) and the unstable distribution
(sid), these problems have been fixed in version
4.1.3~rc1+hg-20120614.a9c0a89c08f2-1.

We recommend that you upgrade your xen packages.

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: http://www.debian.org/security/

Mailing list: debian-security-announce@lists.debian.org
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