By-passing Cross-Site Scripting Protection in HTML Sanitizer

• Component Type: TYPO3 CMS
• Subcomponent: HTML Sanitizer (based on typo3/html-sanitizer)
• Release Date: November 14, 2023
• Vulnerability Type: Cross-Site Scripting
• Affected Versions: 8.7.42-8.7.54, 9.5.29-9.5.43, 10.4.19-10.4.40, 11.3.2-11.5.32, 12.0.0-12.4.7
• Severity: Medium
• Suggested CVSS: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C
• References: CVE-2023-47125, CWE-79

Problem Description

DOM processing instructions are not handled correctly. This allows bypassing the cross-site scripting mechanism of typo3/html-sanitizer.

Solution

Update to TYPO3 versions 8.7.55 ELTS, 9.5.44 ELTS, 10.4.41 ELTS, 11.5.33, 12.4.8 that fix the problem described above.

Credits

Thanks to Yaniv Nizry and Niels Dossche who reported this issue, and to TYPO3 core & security team member Oliver Hader who fixed the issue.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.

General Note

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