=========================================================================Ubuntu Security Notice USN-6138-1
June 05, 2023

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

- Ubuntu 23.04
- Ubuntu 22.10
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in libssh.

Software Description:
- libssh: A tiny C SSH library

Details:

Philip Turnbull discovered that libssh incorrectly handled rekeying with
algorithm guessing. A remote attacker could use this issue to cause libssh
to crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2023-1667)

Kevin Backhouse discovered that libssh incorrectly handled verifying data
signatures. A remote attacker could possibly use this issue to bypass
authorization. (CVE-2023-2283)

Update instructions:

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

Ubuntu 23.04:
   libssh-4                        0.10.4-2ubuntu0.1

Ubuntu 22.10:
   libssh-4                        0.9.6-2ubuntu0.22.10.1

Ubuntu 22.04 LTS:
   libssh-4                        0.9.6-2ubuntu0.22.04.1

Ubuntu 20.04 LTS:
   libssh-4                        0.9.3-2ubuntu2.3

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

References:
   https://ubuntu.com/security/notices/USN-6138-1
   CVE-2023-1667, CVE-2023-2283

Package Information:
   https://launchpad.net/ubuntu/+source/libssh/0.10.4-2ubuntu0.1
   https://launchpad.net/ubuntu/+source/libssh/0.9.6-2ubuntu0.22.10.1
   https://launchpad.net/ubuntu/+source/libssh/0.9.6-2ubuntu0.22.04.1
   https://launchpad.net/ubuntu/+source/libssh/0.9.3-2ubuntu2.3