Moderately Critical XSS Vulnerability in GOV.UK Theme

The Drupal Security Team announced on February 23^rd 2022, a moderately critical Cross-Site Scripting (XSS) vulnerability in the GOV.UK Theme SA-CONTRIB-2022-027. The vulnerability is classified as moderately critical because of the  14∕25 [AC:Basic/A:User/CI:Some/II:Some/E:Theoretical/TD:All] status

The GOV.UK Theme (govuk_theme) is a Drupal theme for the GOV.UK Design System. This theme utilizes the GOV.UK Design System Frontend node module and has Twig template files for the majority of the GOV.UK styles, components, and patterns.

The theme doesn't sanitize user input in certain cases, which leads to Cross-Site-Scripting (XSS) vulnerabilities. Certain entities or configuration can be created or edited to exploit one or more Cross-Site-Scripting (XSS) vulnerabilities targeting visitors to the site, including site admins with privileged access.

The vulnerability is mitigated by the facts, that:

• An attacker must have one of several permissions, of which at least some are commonly only assigned to either editors, site builders or administrators.
• For some of the vulnerabilities, certain contributed modules must be enabled.

Solution: If you use the govuk_theme for Drupal 9.x, upgrade to govuk_theme 8.x-1.9 https://www.drupal.org/project/govuk_theme/releases/8.x-1.9

The vulnerability was reported by Patrick Fey and fixed by Andrew Hughes-Onslow and Patrick Fey. This security fix was coordinated by Chris McCafferty and Damien McKenna of the Drupal Security Team.

Source:

• SA-CONTRIB-2022-027
• GOV.UK Theme