Impact
The Trix editor, in versions prior to 2.1.18, is vulnerable to XSS when a crafted application/x-trix-document JSON payload is dropped into the editor in environments using the fallback Level0InputController (e.g., embedded WebViews lacking Input Events Level 2 support).
The StringPiece.fromJSON method trusted href attributes from the JSON payload without sanitization. An attacker could craft a draggable element containing a javascript: URI in the href attribute that, when dropped into a vulnerable editor, would bypass DOMPurify sanitization and inject executable JavaScript into the DOM.
Exploitation requires a specific environment (Level0InputController fallback) and social engineering (victim must drag and drop attacker-controlled content into the editor). Applications using server-side HTML sanitization (such as Rails' built-in sanitizer) are additionally protected, as the payload is neutralized on save.
Patches
Update Recommendation: Users should upgrade to Trix editor version 2.1.18 or later.
References
The XSS vulnerability was responsibly reported by Hackerone researcher newbiefromcoma.
Impact
The Trix editor, in versions prior to 2.1.18, is vulnerable to XSS when a crafted
application/x-trix-documentJSON payload is dropped into the editor in environments using the fallback Level0InputController (e.g., embedded WebViews lacking Input Events Level 2 support).The
StringPiece.fromJSONmethod trustedhrefattributes from the JSON payload without sanitization. An attacker could craft a draggable element containing ajavascript:URI in the href attribute that, when dropped into a vulnerable editor, would bypass DOMPurify sanitization and inject executable JavaScript into the DOM.Exploitation requires a specific environment (Level0InputController fallback) and social engineering (victim must drag and drop attacker-controlled content into the editor). Applications using server-side HTML sanitization (such as Rails' built-in sanitizer) are additionally protected, as the payload is neutralized on save.
Patches
Update Recommendation: Users should upgrade to Trix editor version 2.1.18 or later.
References
The XSS vulnerability was responsibly reported by Hackerone researcher newbiefromcoma.