A PostgreSQL security update has been released for Ubuntu Linux 16.04 ESM.

USN-5676-1: PostgreSQL vulnerability

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Ubuntu Security Notice USN-5676-1
October 13, 2022

postgresql-9.5 vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 ESM

Summary:

PostgreSQL could be made to execute commands as the superuser.

Software Description:
- postgresql-9.5: Object-relational SQL database

Details:

Alexander Lakhin discovered that PostgreSQL incorrectly handled the
security restricted operation sandbox when a privileged user is maintaining another user’s objects. An attacker having permission to create non-temp objects can use this issue to execute arbitrary commands as the superuser.

Update instructions:

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

Ubuntu 16.04 ESM:
postgresql-9.5 9.5.25-0ubuntu0.16.04.1+esm2

After a standard system update you need to restart PostgreSQL to
make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-5676-1
CVE-2022-1552