Bypassing Cross-Site Scripting Protection in TYPO3 HTML Sanitizer

> ### 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 (4.4)

Problem

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

Solution

Update to typo3/html-sanitizer versions 1.5.3 or 2.1.4 that fix the problem described.

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.

References

• TYPO3-CORE-SA-2023-007
• Context & Details at masterminds/html5