NULL pointer dereference in TagSection.keys() in python-apt on APT-based Linux systems allows a local attacker to cause a denial of service (process crash) via a crafted deb822 file with a malformed non-UTF-8 key.

The remote Debian 11 host has packages installed that are affected by a vulnerability as referenced in the dla-4408 advisory.

    - -----------------------------------------------------------------------     Debian LTS Advisory DLA-4408-1              debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Utkarsh Gupta     December 16, 2025                           https://wiki.debian.org/LTS
    - -----------------------------------------------------------------------

    Package        : python-apt     Version        : 2.2.1.1     CVE ID         : CVE-2025-6966     Debian Bug     : 1122291

    Julian Andres Klode discovered that python-apt, a Python interface to     libapt-pkg, incorrectly handled deb822 configuration files. An attacker     could use this issue to cause python-apt to crash, resulting in a     denial of service.

    For Debian 11 bullseye, this problem has been fixed in version     2.2.1.1.

    We recommend that you upgrade your python-apt packages.

    For the detailed security status of python-apt please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/python-apt

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 host has packages installed that are affected by a vulnerability as referenced in the USN-7916-1 advisory.

    Julian Andres Klode discovered that python-apt incorrectly handled deb822 configuration files. An attacker     could use this issue to cause python-apt to crash, resulting in a denial of service.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - NULL pointer dereference in TagSection.keys() in python-apt on APT-based Linux systems allows a local     attacker to cause a denial of service (process crash) via a crafted deb822 file with a malformed non-UTF-8     key. (CVE-2025-6966)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
278731	Debian dla-4408 : python-apt-common - security update	Nessus	Debian Local Security Checks	medium
278079	Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 : python-apt vulnerability (USN-7916-1)	Nessus	Ubuntu Local Security Checks	medium
277709	Linux Distros Unpatched Vulnerability : CVE-2025-6966	Nessus	Misc.	medium

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