Description
DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions 3.0.1 through 3.3.3 are vulnerable to a prototype pollution-based XSS bypass. When an application uses `DOMPurify.sanitize()` with the default configuration (no `CUSTOM_ELEMENT_HANDLING` option), a prior prototype pollution gadget can inject permissive `tagNameCheck` and `attributeNameCheck` regex values into `Object.prototype`, causing DOMPurify to allow arbitrary custom elements with arbitrary attributes — including event handlers — through sanitization. Version 3.4.0 fixes the issue.
Problem types
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Product status
References
github.com/...Purify/security/advisories/GHSA-v9jr-rg53-9pgp
github.com/...Purify/security/advisories/GHSA-v9jr-rg53-9pgp
github.com/cure53/DOMPurify/releases/tag/3.4.0