An Exim security update has been released for Ubuntu Linux 14.04 LTS, 16.04 LTS, 18.04 LTS, 20.04 LTS, 22.04 LTS, 23.04, and 23.10.

[USN-6455-1] Exim vulnerabilities

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Ubuntu Security Notice USN-6455-1
October 26, 2023

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

- Ubuntu 23.10
- Ubuntu 23.04
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS (Available with Ubuntu Pro)
- Ubuntu 16.04 LTS (Available with Ubuntu Pro)
- Ubuntu 14.04 LTS (Available with Ubuntu Pro)

Summary:

Several security issues were fixed in Exim.

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

Details:

It was discovered that Exim incorrectly handled validation of user-supplied
data, which could lead to memory corruption. A remote attacker could
possibly use this issue to execute arbitrary code. (CVE-2023-42117)

It was discovered that Exim incorrectly handled validation of user-supplied
data, which could lead to an out-of-bounds read. An attacker could possibly
use this issue to expose sensitive information. (CVE-2023-42119)

Update instructions:

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

Ubuntu 23.10:
exim4-daemon-heavy 4.96-17ubuntu2.1
exim4-daemon-light 4.96-17ubuntu2.1

Ubuntu 23.04:
exim4-daemon-heavy 4.96-14ubuntu1.3
exim4-daemon-light 4.96-14ubuntu1.3

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

Ubuntu 20.04 LTS:
exim4-daemon-heavy 4.93-13ubuntu1.9
exim4-daemon-light 4.93-13ubuntu1.9

Ubuntu 18.04 LTS (Available with Ubuntu Pro):
exim4-daemon-heavy 4.90.1-1ubuntu1.10+esm2
exim4-daemon-light 4.90.1-1ubuntu1.10+esm2

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
exim4-daemon-heavy 4.86.2-2ubuntu2.6+esm5
exim4-daemon-light 4.86.2-2ubuntu2.6+esm5

Ubuntu 14.04 LTS (Available with Ubuntu Pro):
exim4-daemon-heavy 4.82-3ubuntu2.4+esm7
exim4-daemon-light 4.82-3ubuntu2.4+esm7

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

References:
https://ubuntu.com/security/notices/USN-6455-1
CVE-2023-42117, CVE-2023-42119

Package Information:
https://launchpad.net/ubuntu/+source/exim4/4.96-17ubuntu2.1
https://launchpad.net/ubuntu/+source/exim4/4.96-14ubuntu1.3
https://launchpad.net/ubuntu/+source/exim4/4.95-4ubuntu2.4
https://launchpad.net/ubuntu/+source/exim4/4.93-13ubuntu1.9