CVE-2021-35955 – contao/core-bundle

Package

Manager: composer
Name: contao/core-bundle
Vulnerable Version: >=4.0.0 <4.4.56 || >=4.5.0 <4.9.18 || >=4.10.0 <4.11.7

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L

EPSS: 0.0031 pctl0.53616

Details

Cross site scripting via HTML attributes in the back end ### Impact It is possible for untrusted users to inject malicious code into HTML attributes in the back end, which will be executed both in the element preview (back end) and on the website (front end). Installations are only affected if there are untrusted back end users who have the rights to modify HTML fields (e.g. TinyMCE). ### Patches Update to Contao 4.4.56, 4.9.18 or 4.11.7 ### Workarounds Disable all fields that allow HTML for untrusted back end users or disable the login for these users. ### References https://contao.org/en/security-advisories/cross-site-scripting-via-html-attributes-in-the-back-end ### For more information If you have any questions or comments about this advisory, open an issue in [contao/contao](https://github.com/contao/contao/issues/new/choose). ### Credits Thanks to Mikhail Khramenkov and Moritz Vondano for reporting this security issue.

Metadata

Created: 2021-08-25T14:45:01Z
Modified: 2025-04-17T12:45:11Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-hr3h-x6gq-rqcp/GHSA-hr3h-x6gq-rqcp.json
CWE IDs: ["CWE-79"]
Alternative ID: GHSA-hr3h-x6gq-rqcp
Finding: F425
Auto approve: 1