CVE-2024-52595 – lxml-html-clean

Package

Manager: pip
Name: lxml-html-clean
Vulnerable Version: >=0 <0.4.0

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00395 pctl0.59603

Details

HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through ### Impact 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. ### Patches Users employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue. ### Workarounds As a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability: * `remove_tags`: Specify tags to remove - their content is moved to their parents' tags. * `kill_tags`: Specify tags to be removed completely. * `allow_tags`: Restrict the set of permissible tags, excluding context-switching tags like `<svg>`, `<math>` and `<noscript>`. ### References * https://github.com/fedora-python/lxml_html_clean/pull/19 * https://github.com/fedora-python/lxml_html_clean/pull/19/commits/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808

Metadata

Created: 2024-11-19T21:07:59Z
Modified: 2025-01-14T16:37:30Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/11/GHSA-5jfw-gq64-q45f/GHSA-5jfw-gq64-q45f.json
CWE IDs: ["CWE-184", "CWE-79", "CWE-83"]
Alternative ID: GHSA-5jfw-gq64-q45f
Finding: F008
Auto approve: 1