Headline
GHSA-j386-3444-qgwg: Trix allows Cross-site Scripting via `javascript:` url in a link
The Trix editor, versions prior to 2.1.11, is vulnerable to XSS when pasting malicious code in the link field.
Impact
An attacker could trick the user to copy&paste a malicious javascript: URL as a link that would execute arbitrary JavaScript code within the context of the user’s session, potentially leading to unauthorized actions being performed or sensitive information being disclosed.
See https://gist.github.com/th4s1s/3921fd9c3e324ad9a3e0d846166e3eb8
Patches
Update Recommendation: Users should upgrade to Trix editor version 2.1.12 or later.
Workarounds
This is not really a workaround but something that should be considered in addition to upgrading to the patched version. If affected users can disallow browsers that don’t support a Content Security Policy, then this would be an effective workaround for this and all XSS vulnerabilities. Set CSP policies such as script-src ‘self’ to ensure that only scripts hosted on the same origin are executed, and explicitly prohibit inline scripts using script-src-elem.
References
https://gist.github.com/th4s1s/3921fd9c3e324ad9a3e0d846166e3eb8
Credits
This vulnerability was reported by Hackerone researcher https://hackerone.com/lio346?type=user
Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.