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Security Advisory

USN-5017-1: Linux kernel vulnerabilities




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 18.04


It was discovered that the virtual file system implementation in the Linux kernel contained an unsigned to signed integer conversion error. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-33909)

It was discovered that the bluetooth subsystem in the Linux kernel did not properly perform access control. An authenticated attacker could possibly use this to expose sensitive information. (CVE-2020-26558, CVE-2021-0129)

CVEs contained in this USN include: CVE-2020-26558, CVE-2021-33909, CVE-2021-0129.

Affected Cloud Foundry Products and Versions

Severity is high unless otherwise noted.

  • Bionic Stemcells
    • 1.x versions prior to 1.20
    • All other stemcells not listed.


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 1.20 or greater
    • All other stemcells should be upgraded to the latest version available on


2021-09-03: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR