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Security Advisory

USN-6244-1: AMD Microcode vulnerability

USN-6244-1: AMD Microcode vulnerability




Canonical Ubuntu

Versions Affected

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


Tavis Ormandy discovered that some AMD processors did not properly handle speculative execution of certain vector register instructions. A local attacker could use this to expose sensitive information. Update Instructions: Run `sudo pro fix USN-6244-1` to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: amd64-microcode – 3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm1 Available with Ubuntu Pro (Infra-only):

CVEs contained in this USN include: CVE-2023-20593.

Affected Cloud Foundry Products and Versions

Severity is high unless otherwise noted.

  • Jammy Stemcells
    • 1.x versions prior to 1.181
    • All other stemcells not listed.
  • CF Deployment
    • All versions with Jammy Stemcells prior to 1.181


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

The Cloud Foundry project recommends upgrading the following releases:

  • Jammy Stemcells
    • Upgrade 1.x versions to 1.181 or greater
    • All other stemcells should be upgraded to the latest version available on
  • CF Deployment
    • For all versions, upgrade Jammy Stemcells to 1.181 or greater


2023-10-05: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR