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Security Advisory

USN-5355-1: zlib vulnerability

USN-5355-1: zlib vulnerability




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 18.04


Danilo Ramos discovered that zlib incorrectly handled memory when performing certain deflating operations. An attacker could use this issue to cause zlib to crash, resulting in a denial of service, or possibly execute arbitrary code.

CVEs contained in this USN include: CVE-2018-25032.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • Bionic Stemcells
    • 1.x versions prior to 1.76
    • All other stemcells not listed.
  • cflinuxfs3
    • All versions prior to 0.280.0
  • CF Deployment
    • All versions prior to 20.0.0, or later versions with Bionic Stemcells prior to 1.76


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 1.76 or greater
    • All other stemcells should be upgraded to the latest version available on
  • cflinuxfs3
    • Upgrade all versions to 0.280.0 or greater
  • CF Deployment
    • Upgrade all versions to 20.0.0 or greater and upgrade Bionic Stemcells to 1.76 or greater


2022-05-23: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR