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Security Advisory

USN-4247-2: python-apt regression

USN-4247-2: python-apt regression




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04


USN-4247-1 fixed vulnerabilities in python-apt. The updated packages caused a regression when attempting to upgrade to a new Ubuntu release. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that python-apt would still use MD5 hashes to validate certain downloaded packages. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could potentially be used to install altered packages. (CVE-2019-15795)

It was discovered that python-apt could install packages from untrusted repositories, contrary to expectations. (CVE-2019-15796)

CVEs contained in this USN include: CVE-2019-15795, CVE-2019-15796.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • Xenial Stemcells
    • 621.x versions prior to 621.55
    • 456.x versions prior to 456.96
    • 315.x versions prior to 315.167
    • 250.x versions prior to 250.181
    • 170.x versions prior to 170.201
    • 97.x versions prior to 97.230
    • 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:

  • Xenial Stemcells
    • Upgrade 621.x versions to 621.55 or greater
    • Upgrade 456.x versions to 456.96 or greater
    • Upgrade 315.x versions to 315.167 or greater
    • Upgrade 250.x versions to 250.181 or greater
    • Upgrade 170.x versions to 170.201 or greater
    • Upgrade 97.x versions to 97.230 or greater
    • All other stemcells should be upgraded to the latest version available on


2020-01-22: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR