=========================================================================Ubuntu Security Notice USN-1130-1
May 10, 2011

exim4 vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 11.04
- Ubuntu 10.10
- Ubuntu 10.04 LTS

Summary:

Exim could be made to run arbitrary code under some conditions.

Software Description:
- exim4: Exim mail transfer agent

Details:

It was discovered that the Exim daemon did not correctly handle format
strings in DKIM headers. An unauthenticated remote attacker could send
specially crafted email to run arbitrary code as the Exim user. The
default compiler options for affected releases reduces the vulnerability
to a denial of service under most conditions.

Update instructions:

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

Ubuntu 11.04:
  exim4-daemon-custom             4.74-1ubuntu1.1
  exim4-daemon-heavy              4.74-1ubuntu1.1
  exim4-daemon-light              4.74-1ubuntu1.1

Ubuntu 10.10:
  exim4-daemon-custom             4.72-1ubuntu1.2
  exim4-daemon-heavy              4.72-1ubuntu1.2
  exim4-daemon-light              4.72-1ubuntu1.2

Ubuntu 10.04 LTS:
  exim4-daemon-custom             4.71-3ubuntu1.2
  exim4-daemon-heavy              4.71-3ubuntu1.2
  exim4-daemon-light              4.71-3ubuntu1.2

In general, a standard system update will make all the necessary changes.

References:
  CVE-2011-1764

Package Information:
  https://launchpad.net/ubuntu/+source/exim4/4.74-1ubuntu1.1
  https://launchpad.net/ubuntu/+source/exim4/4.72-1ubuntu1.2
  https://launchpad.net/ubuntu/+source/exim4/4.71-3ubuntu1.2