CVE-2024-52595: HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through

CVE-2024-52595 · Severity: low · CVSS 3.1 · Published 2024-11-19

lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.0, the HTML Parser in lxml does not properly handle context-switching for special HTML tags such as `<svg>`, `<math>` and `<noscript>`. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content. Users employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue. As a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability. Via `remove_tags`, one may specify tags to remove - their content is moved to their parents' tags. Via `kill_tags`, one may specify tags to be removed completely. Via `allow_tags`, one may restrict the set of permissible tags, excluding context-switching tags like `<svg>`, `<math>` and `<noscript>`.

Technologies: lxml_html_clean (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2024-52595 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2024-52595 being exploited in the wild.
How severe is CVE-2024-52595?
Low severity, with a CVSS score of 3.1, published 19 November 2024.
Which products and versions are affected?
lxml_html_clean (PyPI) ECOSYSTEM:introduced=0,fixed=0.4.0, GIT:introduced=0,fixed=c5d816f86eb3707d72a8ecf5f3823e0daa1b3808|ECOSYSTEM:introduced=0,fixed=0.4.0.
Is there a fix for CVE-2024-52595?
Yes. lxml_html_clean (PyPI): upgrade to 0.4.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2024-52595?
Check whether you run lxml_html_clean (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • lxml_html_clean (PyPI): upgrade to 0.4.0 or later
    pip install "lxml_html_clean>=0.4.0"

Affected products

  • lxml_html_clean (PyPI) ECOSYSTEM:introduced=0,fixed=0.4.0, GIT:introduced=0,fixed=c5d816f86eb3707d72a8ecf5f3823e0daa1b3808|ECOSYSTEM:introduced=0,fixed=0.4.0

Identifiers

  • CVE-2024-52595
  • GHSA-5jfw-gq64-q45f
  • PYSEC-2024-160

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