Ubuntu Security Notice USN-1107-1

6th April, 2011

x11-xserver-utils vulnerability

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

• Ubuntu 10.10



• Ubuntu 10.04 LTS



• Ubuntu 9.10



• Ubuntu 8.04 LTS

Summary

An attacker could send crafted input to xrdb and cause it to run programs
as root.

Software description

• x11-xserver-utils
  - X server utilities
  
  

Details

Sebastian Krahmer discovered that the xrdb utility incorrectly filtered
crafted hostnames. An attacker could use this flaw with a malicious
DHCP server or with a remote xdmcp login and execute arbitrary code,
resulting in root privilege escalation.

Update instructions

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

Ubuntu 10.10:

x11-xserver-utils

7.5+2ubuntu1.1

Ubuntu 10.04 LTS:

x11-xserver-utils

7.5+1ubuntu2.1

Ubuntu 9.10:

x11-xserver-utils

7.4+2ubuntu3.1

Ubuntu 8.04 LTS:

x11-xserver-utils

7.3+2ubuntu0.1

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

References

CVE-2011-0465