An Exim SpamAssassin security update has been released for Ubuntu 16.04 LTS.

USN-4520-1: Exim SpamAssassin vulnerability

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Ubuntu Security Notice USN-4520-1
September 18, 2020

sa-exim vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS

Summary:

Exim SpamAssassin could be made to execute aribitrary code if it
received crafted .cf files/rules.

Software Description:
- sa-exim: SpamAssassin filter for Exim

Details:

It was discovered that Exim SpamAssassin does not properly handle
configuration strings. An attacker could possibly use this issue to
execute arbitrary code. (CVE-2019-19920)

Update instructions:

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

Ubuntu 16.04 LTS:
sa-exim 4.2.1-14+deb8u1build0.16.04.1

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

References:
  https://usn.ubuntu.com/4520-1
CVE-2019-19920

Package Information:
  https://launchpad.net/ubuntu/+source/sa-exim/4.2.1-14+deb8u1build0.16.04.1