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Security Advisory

USN-6565-1: OpenSSH vulnerabilities

USN-6565-1: OpenSSH vulnerabilities




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 22.04


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: Run `sudo pro fix USN-6565-1` to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: openssh-client – 1:8.2p1-4ubuntu0.11 openssh-server – 1:8.2p1-4ubuntu0.11 ssh-askpass-gnome – 1:8.2p1-4ubuntu0.11 ssh – 1:8.2p1-4ubuntu0.11 openssh-tests – 1:8.2p1-4ubuntu0.11 openssh-sftp-server – 1:8.2p1-4ubuntu0.11 No subscription required

CVEs contained in this USN include: CVE-2021-41617, CVE-2023-51385, CVE-2023-51384.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • cflinuxfs4
    • All versions prior to 1.63.0
  • Jammy Stemcells
    • 1.x versions prior to 1.340
    • All other stemcells not listed.
  • CF Deployment
    • All versions with Jammy Stemcells prior to 1.340


Users of affected products are strongly encouraged to follow the mitigations below.

The Cloud Foundry project recommends upgrading the following releases:

  • cflinuxfs4
    • Upgrade all versions to 1.63.0 or greater
  • Jammy Stemcells
    • Upgrade 1.x versions to 1.340 or greater
    • All other stemcells should be upgraded to the latest version available on
  • CF Deployment
    • For all versions, upgrade Jammy Stemcells to 1.340 or greater


2024-02-29: Initial vulnerability report published.


Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR