A PostgreSQL security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, 20.04 LTS, and 20.10.

USN-4633-1: PostgreSQL vulnerabilities

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Ubuntu Security Notice USN-4633-1
November 17, 2020

postgresql-10, postgresql-12, postgresql-9.5 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in PostgreSQL.

Software Description:
- postgresql-12: Object-relational SQL database
- postgresql-10: Object-relational SQL database
- postgresql-9.5: Object-relational SQL database

Details:

Peter Eisentraut discovered that PostgreSQL incorrectly handled connection
security settings. Client applications could possibly be connecting with
certain security parameters dropped, contrary to expectations.
(CVE-2020-25694)

Etienne Stalmans discovered that PostgreSQL incorrectly handled the
security restricted operation sandbox. An authenticated remote attacker
could possibly use this issue to execute arbitrary SQL functions as a
superuser. (CVE-2020-25695)

Nick Cleaton discovered that PostgreSQL incorrectly handled the \gset
meta-command. A remote attacker with a compromised server could possibly
use this issue to execute arbitrary code. (CVE-2020-25696)

Update instructions:

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

Ubuntu 20.10:
postgresql-12 12.5-0ubuntu0.20.10.1

Ubuntu 20.04 LTS:
postgresql-12 12.5-0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
postgresql-10 10.15-0ubuntu0.18.04.1

Ubuntu 16.04 LTS:
postgresql-9.5 9.5.24-0ubuntu0.16.04.1

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://usn.ubuntu.com/4633-1
CVE-2020-25694, CVE-2020-25695, CVE-2020-25696

Package Information:
  https://launchpad.net/ubuntu/+source/postgresql-12/12.5-0ubuntu0.20.10.1
  https://launchpad.net/ubuntu/+source/postgresql-12/12.5-0ubuntu0.20.04.1
  https://launchpad.net/ubuntu/+source/postgresql-10/10.15-0ubuntu0.18.04.1
  https://launchpad.net/ubuntu/+source/postgresql-9.5/9.5.24-0ubuntu0.16.04.1