Ubuntu Security Notice USN-1334-1

19th January, 2012

libxml2 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

• Ubuntu 11.10
• Ubuntu 11.04
• Ubuntu 10.10
• Ubuntu 10.04 LTS
• Ubuntu 8.04 LTS

Summary

Applications using libxml2 could be made to crash or run programs as your login if they opened a specially crafted file.

Software description

• libxml2 - GNOME XML library

Details

It was discovered that libxml2 contained an off by one error. If a user or
application linked against libxml2 were tricked into opening a specially
crafted XML file, an attacker could cause the application to crash or
possibly execute arbitrary code with the privileges of the user invoking
the program. (CVE-2011-0216)

It was discovered that libxml2 is vulnerable to double-free conditions
when parsing certain XML documents. This could allow a remote attacker to
cause a denial of service. (CVE-2011-2821, CVE-2011-2834)

It was discovered that libxml2 did not properly detect end of file when
parsing certain XML documents. An attacker could exploit this to crash
applications linked against libxml2. (CVE-2011-3905)

It was discovered that libxml2 did not properly decode entity references
with long names. If a user or application linked against libxml2 were
tricked into opening a specially crafted XML file, an attacker could cause
the application to crash or possibly execute arbitrary code with the
privileges of the user invoking the program. (CVE-2011-3919)

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 11.10:

libxml2 2.7.8.dfsg-4ubuntu0.1

Ubuntu 11.04:

libxml2 2.7.8.dfsg-2ubuntu0.2

Ubuntu 10.10:

libxml2 2.7.7.dfsg-4ubuntu0.3

Ubuntu 10.04 LTS:

libxml2 2.7.6.dfsg-1ubuntu1.3

Ubuntu 8.04 LTS:

libxml2 2.6.31.dfsg-2ubuntu1.7

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

CVE-2011-0216, CVE-2011-2821, CVE-2011-2834, CVE-2011-3905, CVE-2011-3919