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Security Advisory

USN-5828-1: Kerberos vulnerabilities




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04
  • Canonical Ubuntu 18.04
  • Canonical Ubuntu 22.04


It was discovered that Kerberos incorrectly handled certain S4U2Self requests. An attacker could possibly use this issue to cause a denial of service. This issue was only addressed in Ubuntu 16.04 ESM and Ubuntu 18.04 LTS. (CVE-2018-20217) Greg Hudson discovered that Kerberos PAC implementation incorrectly handled certain parsing operations. A remote attacker could use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2022-42898) Update Instructions: Run `sudo pro fix USN-5828-1` to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: libkadm5srv-mit9 – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-doc – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-user – 1.13.2+dfsg-5ubuntu2.2+esm3 libgssrpc4 – 1.13.2+dfsg-5ubuntu2.2+esm3 libkrb5support0 – 1.13.2+dfsg-5ubuntu2.2+esm3 libk5crypto3 – 1.13.2+dfsg-5ubuntu2.2+esm3 libkrb5-dev – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-pkinit – 1.13.2+dfsg-5ubuntu2.2+esm3 libkrb5-3 – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-kdc-ldap – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-otp – 1.13.2+dfsg-5ubuntu2.2+esm3 libkadm5clnt-mit9 – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-gss-samples – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-multidev – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-locales – 1.13.2+dfsg-5ubuntu2.2+esm3 libgssapi-krb5-2 – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-kdc – 1.13.2+dfsg-5ubuntu2.2+esm3 libkrad-dev – 1.13.2+dfsg-5ubuntu2.2+esm3 libkdb5-8 – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-k5tls – 1.13.2+dfsg-5ubuntu2.2+esm3 libkrad0 – 1.13.2+dfsg-5ubuntu2.2+esm3 krb5-admin-server – 1.13.2+dfsg-5ubuntu2.2+esm3 Available with Ubuntu Pro (Infra-only):

CVEs contained in this USN include: CVE-2018-20217, CVE-2022-42898.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • Bionic Stemcells
    • 1.x versions prior to 1.174
    • All other stemcells not listed.
  • cflinuxfs3
    • All versions prior to 0.351.0
  • cflinuxfs4
    • All versions prior to 0.62.0
  • Jammy Stemcells
    • 1.x versions prior to 1.83
    • All other stemcells not listed.
  • CF Deployment
    • All versions prior to 26.4.0, or later versions with Jammy Stemcells prior to 1.83, Bionic Stemcells prior to 1.174, or Xenial Stemcells prior to 621.418


Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

  • Bionic Stemcells
    • Upgrade 1.x versions to 1.174 or greater
    • All other stemcells should be upgraded to the latest version available on
  • cflinuxfs3
    • Upgrade all versions to 0.351.0 or greater
  • cflinuxfs4
    • Upgrade all versions to 0.62.0 or greater
  • Jammy Stemcells
    • Upgrade 1.x versions to 1.83 or greater
    • All other stemcells should be upgraded to the latest version available on
  • CF Deployment
    • Upgrade all versions to 26.4.0 or greater, upgrade Jammy Stemcells to 1.83 or greater, upgrade Bionic Stemcells to 1.174 or greater, and upgrade Xenial Stemcells to 621.418 or greater



2023-02-24: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR