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The CVE-2025-XXXX vulnerability in svg-sanitizer arises due to improper case-sensitive handling of SVG attribute names during sanitization. The library checks only lowercase variants (e.g., xlink:href) but fails to recognize mixed-case or uppercase variants (e.g., xlink:HrEf). This oversight allows attackers to bypass the `isHrefSafeValue` check, leading to potential XSS attacks or unauthorized external resource linking. The flaw exists in the sanitization logic at Sanitizer.php, where attribute name comparisons are not case-insensitive. Attackers can craft malicious SVG files with obfuscated attribute names to evade detection.
DailyCVE Form:
Platform: svg-sanitizer
Version: <= 0.21.0
Vulnerability: Attribute bypass
Severity: Moderate
Date: Aug 12, 2025
Prediction: Patch by Sep 2025
What Undercode Say:
grep -r "isHrefSafeValue" /path/to/svg-sanitizer curl -X POST -d "<svg xlink:HrEf='javascript:alert(1)'/>" http://target.com/upload
How Exploit:
Craft SVG with mixed-case attributes to bypass sanitization.
Protection from this CVE:
Update to patched version.
Impact:
XSS, external resource linking.
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Sources:
Reported By: github.com
Extra Source Hub:
Undercode
