TYPO3 HTML Sanitizer vulnerable to Cross-Site Scripting
Date: 2022-12
Affected: composer/typo3/cms, composer/typo3/cms, composer/typo3/cms
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2022-23499
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)

### Problem Due to a parsing issue in the upstream package [`masterminds/html5`](https://packagist.org/packages/masterminds/html5), malicious markup used in a sequence with special HTML CDATA sections cannot be filtered and sanitized. This allows bypassing the cross-site scripting mechanism of [`typo3/html-sanitizer`](https://packagist.org/packages/typo3/html-sanitizer). Besides that, the upstream package `masterminds/html5` provides HTML raw text elements (`script`, `style`, `noframes`, `noembed` and `iframe`) as DOMText nodes, which were not processed and sanitized further. None of the mentioned elements were defined in the default builder configuration, that's why only custom behaviors, using one of those tag names, were vulnerable to cross-site scripting. ### Solution Update to `typo3/html-sanitizer` versions 1.5.0 or 2.1.1 that fix the problem described.


Mitigations:

Architectural layers (MAESTRO):