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Security Advisory

USN-6541-2: GNU C Library regression




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 22.04


USN-6541-1 fixed vulnerabilities in the GNU C Library. Unfortunately, changes made to allow proper application of the fix for CVE-2023-4806 in Ubuntu 22.04 LTS introduced an issue in the NSCD service IPv6 processing functionalities. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that the GNU C Library was not properly handling certain memory operations. An attacker could possibly use this issue to cause a denial of service (application crash). (CVE-2023-4806, CVE-2023-4813) It was discovered that the GNU C library was not properly implementing a fix for CVE-2023-4806 in certain cases, which could lead to a memory leak. An attacker could possibly use this issue to cause a denial of service (application crash). This issue only affected Ubuntu 22.04 LTS and Ubuntu 23.04. (CVE-2023-5156) Update Instructions: Run `sudo pro fix USN-6541-2` to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: libc-bin – 2.35-0ubuntu3.6 glibc-doc – 2.35-0ubuntu3.6 locales-all – 2.35-0ubuntu3.6 libc6-i386 – 2.35-0ubuntu3.6 libc6-s390 – 2.35-0ubuntu3.6 libc6-dev-i386 – 2.35-0ubuntu3.6 nscd – 2.35-0ubuntu3.6 libc6-dev-x32 – 2.35-0ubuntu3.6 libc6-dev – 2.35-0ubuntu3.6 libc6-amd64 – 2.35-0ubuntu3.6 libc6-x32 – 2.35-0ubuntu3.6 libc6-dev-amd64 – 2.35-0ubuntu3.6 libc-dev-bin – 2.35-0ubuntu3.6 libc6 – 2.35-0ubuntu3.6 libc6-prof – 2.35-0ubuntu3.6 libc-devtools – 2.35-0ubuntu3.6 glibc-source – 2.35-0ubuntu3.6 libc6-dev-s390 – 2.35-0ubuntu3.6 locales – 2.35-0ubuntu3.6 No subscription required

Affected Cloud Foundry Products and Versions

Severity is unknown unless otherwise noted.

  • cflinuxfs4
    • All versions prior to 1.64.0
  • Jammy Stemcells
    • 1.x versions prior to 1.351
    • All other stemcells not listed.
  • CF Deployment
    • All versions with Jammy Stemcells prior to 1.351


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 1.64.0 or greater
  • Jammy Stemcells
    • Upgrade 1.x versions to 1.351 or greater
    • All other stemcells should be upgraded to the latest version available on
  • CF Deployment
    • For all versions, upgrade Jammy Stemcells to 1.351 or greater



2024-02-29: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR