=========================================================================Ubuntu Security Notice USN-5741-1
November 24, 2022

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

- Ubuntu 22.10
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Exim could be made to crash or run programs if it processed specially
crafted regular expressions.

Software Description:
- exim4: Exim is a mail transport agent

Details:

It was discovered that Exim incorrectly handled certain regular
expressions. An attacker could use this issue to cause Exim to crash,
resulting in a denial of service, or possibly execute arbitrary code.

Update instructions:

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

Ubuntu 22.10:
   exim4-base                      4.96-3ubuntu1.1
   exim4-daemon-heavy              4.96-3ubuntu1.1
   exim4-daemon-light              4.96-3ubuntu1.1

Ubuntu 22.04 LTS:
   exim4-base                      4.95-4ubuntu2.2
   exim4-daemon-heavy              4.95-4ubuntu2.2
   exim4-daemon-light              4.95-4ubuntu2.2

Ubuntu 20.04 LTS:
   exim4-base                      4.93-13ubuntu1.7
   exim4-daemon-heavy              4.93-13ubuntu1.7
   exim4-daemon-light              4.93-13ubuntu1.7

Ubuntu 18.04 LTS:
   exim4-base                      4.90.1-1ubuntu1.10
   exim4-daemon-heavy              4.90.1-1ubuntu1.10
   exim4-daemon-light              4.90.1-1ubuntu1.10

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

References:
   https://ubuntu.com/security/notices/USN-5741-1
   CVE-2022-3559

Package Information:
   https://launchpad.net/ubuntu/+source/exim4/4.96-3ubuntu1.1
   https://launchpad.net/ubuntu/+source/exim4/4.95-4ubuntu2.2
   https://launchpad.net/ubuntu/+source/exim4/4.93-13ubuntu1.7
   https://launchpad.net/ubuntu/+source/exim4/4.90.1-1ubuntu1.10