libxml2 - several vulnerabilities

Yang Dingning discovered a double free in libxml’s Xpath processing,
which might allow the execution of arbitrary code.

For the stable distribution (lenny), this problem has been fixed
in version 2.6.32.dfsg-5+lenny3.

For the upcoming stable distribution (squeeze) and the unstable
distribution (sid), this problem has been fixed in version
2.7.8.dfsg-2.

We recommend that you upgrade your libxml2 packages.

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