A PostgreSQL security update has been released for Ubuntu Linux 20.04 LTS, 22.04 LTS, and 23.04.

[USN-6296-1] PostgreSQL vulnerabilities

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Ubuntu Security Notice USN-6296-1
August 17, 2023

postgresql-12, postgresql-14, postgresql-15 vulnerabilities
==========================================================================

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

- Ubuntu 23.04
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in PostgreSQL.

Software Description:
- postgresql-15: Object-relational SQL database
- postgresql-14: Object-relational SQL database
- postgresql-12: Object-relational SQL database

Details:

It was discovered that PostgreSQL incorrectly handled certain extension
script substitutions. An attacker having database-level CREATE privileges
can use this issue to execute arbitrary code as the bootstrap superuser.
(CVE-2023-39417)

It was discovered that PostgreSQL incorrectly handled the MERGE command. A
remote attacker could possibly use this issue to bypass certain UPDATE and
SELECT policies. This issue only affected Ubuntu 23.04. (CVE-2023-39418)

Update instructions:

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

Ubuntu 23.04:
postgresql-15 15.4-0ubuntu0.23.04.1
postgresql-client-15 15.4-0ubuntu0.23.04.1

Ubuntu 22.04 LTS:
postgresql-14 14.9-0ubuntu0.22.04.1
postgresql-client-14 14.9-0ubuntu0.22.04.1

Ubuntu 20.04 LTS:
postgresql-12 12.16-0ubuntu0.20.04.1
postgresql-client-12 12.16-0ubuntu0.20.04.1

This update uses a new upstream release, which includes additional bug
fixes. After a standard system update you need to restart PostgreSQL to
make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-6296-1
CVE-2023-39417, CVE-2023-39418

Package Information:
https://launchpad.net/ubuntu/+source/postgresql-15/15.4-0ubuntu0.23.04.1
https://launchpad.net/ubuntu/+source/postgresql-14/14.9-0ubuntu0.22.04.1
https://launchpad.net/ubuntu/+source/postgresql-12/12.16-0ubuntu0.20.04.1