A PostgreSQL security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, 20.10, and 21.04.

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Ubuntu Security Notice USN-4972-1
June 01, 2021

postgresql-10, postgresql-12, postgresql-13 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.04
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in PostgreSQL.

Software Description:
- postgresql-13: Object-relational SQL database
- postgresql-12: Object-relational SQL database
- postgresql-10: Object-relational SQL database

Details:

Tom Lane discovered that PostgreSQL incorrect handled certain array
subscripting calculations. An authenticated attacker could possibly use
this issue to overwrite server memory and escalate privileges.
(CVE-2021-32027)

Andres Freund discovered that PostgreSQL incorrect handled certain
INSERT ... ON CONFLICT ... DO UPDATE commands. A remote attacker could
possibly use this issue to read server memory and obtain sensitive
information. (CVE-2021-32028)

Tom Lane discovered that PostgreSQL incorrect handled certain UPDATE ...
RETURNING commands. A remote attacker could possibly use this issue to read
server memory and obtain sensitive information. This issue only affected
Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-32029)

Update instructions:

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

Ubuntu 21.04:
postgresql-13 13.3-0ubuntu0.21.04.1

Ubuntu 20.10:
postgresql-12 12.7-0ubuntu0.20.10.1

Ubuntu 20.04 LTS:
postgresql-12 12.7-0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
postgresql-10 10.17-0ubuntu0.18.04.1

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-4972-1
CVE-2021-32027, CVE-2021-32028, CVE-2021-32029

Package Information:
  https://launchpad.net/ubuntu/+source/postgresql-13/13.3-0ubuntu0.21.04.1
  https://launchpad.net/ubuntu/+source/postgresql-12/12.7-0ubuntu0.20.10.1
  https://launchpad.net/ubuntu/+source/postgresql-12/12.7-0ubuntu0.20.04.1
  https://launchpad.net/ubuntu/+source/postgresql-10/10.17-0ubuntu0.18.04.1