==========================================================================
Ubuntu Security Notice USN-6565-1
January 03, 2024

openssh vulnerabilities
==========================================================================

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:

Several security issues were fixed in OpenSSH.

Software Description:
- openssh: secure shell (SSH) for secure access to remote machines

Details:

It was discovered that OpenSSH incorrectly handled supplemental groups when
running helper programs for AuthorizedKeysCommand and
AuthorizedPrincipalsCommand as a different user. An attacker could possibly
use this issue to escalate privileges. This issue only affected Ubuntu
20.04 LTS. (CVE-2021-41617)

It was discovered that OpenSSH incorrectly added destination constraints
when PKCS#11 token keys were added to ssh-agent, contrary to expectations.
This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.
(CVE-2023-51384)

It was discovered that OpenSSH incorrectly handled user names or host names
with shell metacharacters. An attacker could possibly use this issue to
perform OS command injection. (CVE-2023-51385)

Update instructions:

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

Ubuntu 23.10:
   openssh-client                  1:9.3p1-1ubuntu3.2
   openssh-server                  1:9.3p1-1ubuntu3.2

Ubuntu 23.04:
   openssh-client                  1:9.0p1-1ubuntu8.7
   openssh-server                  1:9.0p1-1ubuntu8.7

Ubuntu 22.04 LTS:
   openssh-client                  1:8.9p1-3ubuntu0.6
   openssh-server                  1:8.9p1-3ubuntu0.6

Ubuntu 20.04 LTS:
   openssh-client                  1:8.2p1-4ubuntu0.11
   openssh-server                  1:8.2p1-4ubuntu0.11

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

References:
   https://ubuntu.com/security/notices/USN-6565-1
   CVE-2021-41617, CVE-2023-51384, CVE-2023-51385

Package Information:
   https://launchpad.net/ubuntu/+source/openssh/1:9.3p1-1ubuntu3.2
   https://launchpad.net/ubuntu/+source/openssh/1:9.0p1-1ubuntu8.7
   https://launchpad.net/ubuntu/+source/openssh/1:8.9p1-3ubuntu0.6
   https://launchpad.net/ubuntu/+source/openssh/1:8.2p1-4ubuntu0.11