TYPO3 HTML Sanitizer Bypasses Cross-Site Scripting Protection
Date: 2022-09
Affected: composer/typo3/cms, composer/typo3/cms, composer/typo3/cms-core
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2022-36020
CWE: CWE-79
CVSS: 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)

> ### Meta > * CVSS: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C` (5.7) ### Problem Due to a parsing issue in upstream package [`masterminds/html5`](https://packagist.org/packages/masterminds/html5), malicious markup used in a sequence with special HTML comments cannot be filtered and sanitized. This allows to by-pass the cross-site scripting mechanism of `typo3/html-sanitizer`. ### Solution Update to `typo3/html-sanitizer` versions 1.0.7 or 2.0.16 that fix the problem described. ### Credits Thanks to David Klein who reported this issue, and to TYPO3 security team member Oliver Hader who fixed the issue.


Mitigations:

Architectural layers (MAESTRO):