A libssh security update has been released for Ubuntu Linux 20.04 LTS, 22.04 LTS, 22.10, and 23.04.

[USN-6138-1] libssh vulnerabilities

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

libssh vulnerabilities
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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