CVE-2024-52595

Summary

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>.

Affected Software

VendorProductVersion RangeStatus
fedora-pythonlxml_html_clean< 0.4.0affected

Weaknesses

  • CWE-79: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-83: CWE-83: Improper Neutralization of Script in Attributes in a Web Page
  • CWE-184: CWE-184: Incomplete List of Disallowed Inputs

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References