Medium CVSS 4.3

Overview

Incomplete blacklist vulnerability in Sanitizer::checkCss in MediaWiki before 1.19.9, 1.20.x before 1.20.8, and 1.21.x before 1.21.3 allows remote attackers to conduct cross-site scripting (XSS) attacks via certain non-ASCII characters in CSS, as demonstrated using variations of "expression" containing (1) full width characters or (2) IPA extensions, which are converted and rendered by Internet Explorer.

Risk analysis

This vulnerability is rated 🟡 MEDIUM.

  • CVSS: 4.3 (MEDIUM)
  • Detected tags: none (tag impact: LOW)

Recommended actions:

  • Prioritize remediation based on business criticality and exposure.
  • Limit exposure and increase monitoring until fixed.

Recommended tools

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