A man-db security update has been released for Ubuntu 16.04 ESM.

USN-5334-1: man-db vulnerability

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Ubuntu Security Notice USN-5334-1
March 17, 2022

man-db vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 ESM

Summary:

man-db could be made to overwrite file and directory permissions.

Software Description:
- man-db: on-line manual pager

Details:

It was discovered that man-db incorrectly handled permission changing
operations in its daily cron job, and was therefore affected by a race
condition. An attacker could possibly use this issue to escalate privileges
and execute arbitrary code.

Update instructions:

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

Ubuntu 16.04 ESM:
man-db 2.7.5-1ubuntu0.1~esm1

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

References:
https://ubuntu.com/security/notices/USN-5334-1
CVE-2015-1336