A GnuTLS security update has been released for Ubuntu Linux 20.04 LTS, 22.04 LTS, 23.04, and 23.10.

[USN-6499-1] GnuTLS vulnerability

==========================================================================
Ubuntu Security Notice USN-6499-1
November 21, 2023

gnutls28 vulnerability
==========================================================================

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

- Ubuntu 23.10
- Ubuntu 23.04
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

GnuTLS could be made to expose sensitive information over the network.

Software Description:
- gnutls28: GNU TLS library

Details:

It was discovered that GnuTLS had a timing side-channel when handling
certain RSA-PSK key exchanges. A remote attacker could possibly use this
issue to recover sensitive information.

Update instructions:

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

Ubuntu 23.10:
libgnutls30 3.8.1-4ubuntu1.1

Ubuntu 23.04:
libgnutls30 3.7.8-5ubuntu1.1

Ubuntu 22.04 LTS:
libgnutls30 3.7.3-4ubuntu1.3

Ubuntu 20.04 LTS:
libgnutls30 3.6.13-2ubuntu1.9

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

References:
https://ubuntu.com/security/notices/USN-6499-1
CVE-2023-5981

Package Information:
https://launchpad.net/ubuntu/+source/gnutls28/3.8.1-4ubuntu1.1
https://launchpad.net/ubuntu/+source/gnutls28/3.7.8-5ubuntu1.1
https://launchpad.net/ubuntu/+source/gnutls28/3.7.3-4ubuntu1.3
https://launchpad.net/ubuntu/+source/gnutls28/3.6.13-2ubuntu1.9