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USN-6565-1: OpenSSH vulnerabilities

3 January 2024

Several security issues were fixed in OpenSSH.

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Releases

Packages

  • 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)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 23.10
Ubuntu 23.04
Ubuntu 22.04
Ubuntu 20.04

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

Related notices

  • USN-5666-1: openssh-sftp-server, openssh, openssh-client-ssh1, openssh-server, ssh-krb5, ssh-askpass-gnome, openssh-client, ssh
  • USN-6560-2: openssh-sftp-server, openssh, openssh-client-ssh1, openssh-server, ssh-krb5, ssh-askpass-gnome, openssh-client, ssh