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Security Advisory

USN-5806-2: Ruby vulnerability




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 18.04
  • Canonical Ubuntu 22.04


USN-5806-1 fixed vulnerabilities in Ruby. This update fixes the problem for Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 22.10. Original advisory details: Hiroshi Tokumaru discovered that Ruby did not properly handle certain user input for applications which generate HTTP responses using cgi gem. An attacker could possibly use this issue to maliciously modify the response a user would receive from a vulnerable application. Update Instructions: Run `sudo pro fix USN-5806-2` to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: libruby2.5 – 2.5.1-1ubuntu1.13 ruby2.5 – 2.5.1-1ubuntu1.13 ruby2.5-doc – 2.5.1-1ubuntu1.13 ruby2.5-dev – 2.5.1-1ubuntu1.13 No subscription required

CVEs contained in this USN include: CVE-2021-33621.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • cflinuxfs3
    • All versions prior to 0.351.0
  • cflinuxfs4
    • All versions prior to 0.60.0
  • CF Deployment
    • All versions prior to 26.4.0


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 0.351.0 or greater
  • cflinuxfs4
    • Upgrade all versions to 0.60.0 or greater
  • CF Deployment
    • Upgrade all versions to 26.4.0 or greater



2023-02-24: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR