What happened
rails-html-sanitizer is responsible for sanitizing HTML fragments in Rails applications. From 1.0.3 until 1.7.1, Rails::HTML::PermitScrubber restricted SVG reference elements in SVG_ALLOW_LOCAL_HREF only when they used xlink:href, even though browsers also accept the plain href attribute. Applications with non-default allowed tags that included SVG use or feImage elements could therefore permit external references; a same-origin external SVG referenced by use could execute scripts in the sanitized document's context, while feImage could load external images for tracking. Applications using the default allowed tags are not affected. This issue is fixed in version 1.7.1.
Affected versions
rails-html-sanitizer: >= 1.0.3, < 1.7.1 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.