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Security Advisory

USN-4705-1: Sudo vulnerabilities




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04
  • Canonical Ubuntu 18.04


It was discovered that Sudo incorrectly handled memory when parsing command lines. A local attacker could possibly use this issue to obtain unintended access to the administrator account. (CVE-2021-3156)

It was discovered that the Sudo sudoedit utility incorrectly handled checking directory permissions. A local attacker could possibly use this issue to bypass file permissions and determine if a directory exists or not. (CVE-2021-23239)

CVEs contained in this USN include: CVE-2021-3156, CVE-2021-23239.

Affected Cloud Foundry Products and Versions

Severity is high unless otherwise noted.

  • cflinuxfs3
    • All versions prior to 0.222.0
  • Xenial Stemcells
    • 456.x versions prior to 456.135
    • 621.x versions prior to 621.99
    • All other stemcells not listed.
  • CF Deployment
    • All versions prior to 16.0.0


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

  • cflinuxfs3
    • Upgrade All versions to 0.222.0 or greater
  • Xenial Stemcells
    • Upgrade 456.x versions to 456.135 or greater
    • Upgrade 621.x versions to 621.99 or greater
    • All other stemcells should be upgraded to the latest version available on
  • CF Deployment
    • Upgrade All versions to 16.0.0 or greater


2021-02-10: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR