Security Advisories

Backdrop core Link field attributes may not be sufficiently sanitized in specialized scenarios, which can lead to a Cross Site Scripting vulnerability (XSS).

This vulnerability is not directly exploitable within core itself, nor are there any contributed modules that appear to exhibit the behavior. This is a security hardening to prevent such attacks in the future. This problem has not been reproducible without a specialized module. 

Sites are not affected if they are not extending the Link field module in ways that provide the ability to input additional link attributes.

Backdrop CMS includes bulk operations for content that allow people to modify multiple nodes at once from the Manage Content page (admin/content). These bulk operations can also be added to other listings using Views.

A bug in the core Actions system allows some people to use bulk actions to modify some values that they would not have permission to modify when editing individual nodes.

This vulnerability is mitigated by the fact that an attacker must have permission to access the /admin/content page, or other custom views used to modify nodes.

In particular, the following bulk actions now require either the "Administer content" permission, or the "Bypass content access control" permission.

• Make content sticky
• Make content unsticky
• Promote content
• Remove promotion
• Publish content
• Unpublish content
• Delete content

The Mail Disguise module enables a Backdrop website to obfuscate email addresses, and should prevent spambots from collecting them. The module doesn't sufficiently validate the data attribute value on links, potentially leading to a Cross Site Scripting (XSS) vulnerability.

This is mitigated by the fact an attacker must be able to insert link (<a>) HTML elements containing data attributes into the page.

The Masquerade module allows people to temporarily switch to another user account.

The module provides a "Masquerade as admin" permission to restrict people who can masquerade from switching to an account with administrative privileges. This permission is not always honored and may allow non-administrative users to masquerade as an administrator.

This vulnerability is mitigated by the fact that an attacker must have a role with the "Masquerade as user" permission.

The Bootstrap Lite Backdrop CMS theme doesn't sufficiently sanitize certain class names.

The Bootstrap 5 Lite Backdrop CMS theme doesn't sufficiently sanitize certain class names.

The Link iframe formatter module doesn't sufficiently sanitize user input before displaying results to the screen.

This vulnerability is mitigated by the fact that an attacker must have the ability to create content containing an iFrame field.

The GDPR cookies module contains a library with known vulnerabilities:

• https://security.snyk.io/vuln/SNYK-JS-TARTEAUCITRONJS-5772112
• https://security.snyk.io/vuln/SNYK-JS-TARTEAUCITRONJS-8366541

tarteaucitronjs is a package that provides compliance to the European cookie law.  Affected versions of this package are vulnerable to Cross-site Scripting (XSS) due to missing sanitization of the services attributes value, and improper user-input sanitization, via width, theme, controls, img and other attributes.

This module enables you to integrate the site with the Google Tag Manager (GTM) application.

The module doesn't have the "restrict access" flag on the "administer google_tag_container" permission. A user with this permission can load a GTM container that completely changes the page or inserts malicious JS, resulting in a cross site scripting vulnerability.

This vulnerability is mitigated by the fact that an attacker must have a role with the aforementioned permission.

Backdrop CMS does not sufficiently validate uploaded SVG images to ensure they do not contain potentially dangerous SVG tags. SVG images can contain clickable links and executable scripting, and using a crafted SVG, it is possible to execute scripting in the browser when an SVG image is viewed.

This issue is mitigated by the attacker needing to be able to upload SVG images, and that Backdrop embeds all uploaded SVG images within <img> tags, which prevents scripting from executing. The SVG must be viewed directly by its URL in order to run any embedded scripting.