Sabberworm PHP CSS Parser before 8.3.1 calls eval on uncontrolled data, possibly leading to remote code execution if the function allSelectors() or getSelectorsBySpecificity() is called with input from an attacker.

The remote Debian 11 host has a package installed that is affected by a vulnerability as referenced in the dla-4333 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4333-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                   Andreas Henriksson     October 14, 2025                              https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : php-horde-css-parser     Version        : 1.0.11-8+deb11u1     CVE ID         : CVE-2020-13756     Debian Bug     :

    Sabberworm PHP CSS Parser before 8.3.1 calls eval on uncontrolled data,     possibly leading to remote code execution if the function allSelectors() or     getSelectorsBySpecificity() is called with input from an attacker.

    The php-horde-css-parser bundles the Sabberworm PHP CSS Parser code and     is thus also vulnerable.

    For Debian 11 bullseye, this problem has been fixed in version     1.0.11-8+deb11u1.

    We recommend that you upgrade your php-horde-css-parser packages.

    For the detailed security status of php-horde-css-parser please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/php-horde-css-parser

    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     Attachment:
    signature.asc     Description: PGP signature

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

  - Sabberworm PHP CSS Parser before 8.3.1 calls eval on uncontrolled data, possibly leading to remote code     execution if the function allSelectors() or getSelectorsBySpecificity() is called with input from an     attacker. (CVE-2020-13756)

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

The remote Ubuntu 16.04 LTS / 18.04 LTS host has a package installed that is affected by a vulnerability as referenced in the USN-7502-1 advisory.

    It was discovered that Horde Css Parser did not correctly handle parsing uncontrolled CSS data. An     attacker could possibly use this issue to perform remote code execution. (CVE-2020-13756)

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.

ID	Name	Product	Family	Severity
270348	Debian dla-4333 : php-horde-css-parser - security update	Nessus	Debian Local Security Checks	critical
256894	Linux Distros Unpatched Vulnerability : CVE-2020-13756	Nessus	Misc.	critical
235491	Ubuntu 16.04 LTS / 18.04 LTS : Horde Css Parser vulnerability (USN-7502-1)	Nessus	Ubuntu Local Security Checks	critical

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CVE-2020-13756

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