CVE-2023-38500: By-passing Cross-Site Scripting Protection in 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 Due to an encoding issue in the serialization layer, malicious markup nested in a noscript element was not encoded correctly. noscript is disabled in the default configuration, but might have been enabled in custom scenarios. This allows bypassing the cross-site scripting mechanism of typo3/html-sanitizer.
Solution Update to typo3/html-sanitizer versions 1.5.1 or 2.1.2 that fix the problem described.
Credits Thanks to David Klein and Yaniv Nizry who reported this issue, and to TYPO3 security team members Oliver Hader and Benjamin Franzke who fixed the issue.
References TYPO3-CORE-SA-2023-002
Other sources
TYPO3 HTML Sanitizer is an HTML sanitizer, written in PHP, aiming to provide cross-site-scripting-safe markup based on explicitly allowed tags, attributes and values. Starting in version 1.0.0 and prior to versions 1.5.1 and 2.1.2, due to an encoding issue in the serialization layer, malicious markup nested in a noscript element was not encoded correctly. noscript is disabled in the default configuration, but might have been enabled in custom scenarios. This allows bypassing the cross-site scripting mechanism of TYPO3 HTML Sanitizer. Versions 1.5.1 and 2.1.2 fix the problem.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2023-38500?
The severity of CVE-2023-38500 is medium with a CVSS score of 6.1.
What is the affected software for CVE-2023-38500?
The affected software for CVE-2023-38500 is TYPO3 HTML Sanitizer versions between 2.0.0 and 2.1.2, and versions between 1.0.0 and 1.5.1.
How can I fix CVE-2023-38500?
To fix CVE-2023-38500, update TYPO3 HTML Sanitizer to version 2.1.2 for versions 2.0.0 to 2.1.2, or update to version 1.5.1 for versions 1.0.0 to 1.5.1.
What is the Common Weakness Enumeration (CWE) for CVE-2023-38500?
The CWE for CVE-2023-38500 is CWE-79 (Improper Neutralization of Input During Web Page Generation).
Where can I find more information about CVE-2023-38500?
You can find more information about CVE-2023-38500 in the following references: [GitHub Security Advisory](https://github.com/TYPO3/html-sanitizer/security/advisories/GHSA-59jf-3q9v-rh6g), [GitHub Commit](https://github.com/TYPO3/html-sanitizer/commit/e3026f589fef0be8c3574ee3f0a0bfbe33d7ebdb), [TYPO3 Security Advisory](https://typo3.org/security/advisory/typo3-core-sa-2023-002).