Ruby on Rails: XSS vulnerability in sanitize-method when parsing link's href

Possible XSS vulnerability in rails-html-sanitizer

There is a possible XSS vulnerability in rails-html-sanitizer. This
vulnerability has been assigned the CVE identifier CVE-2018-3741.

Versions Affected: 1.0.3 or older.
Not affected: None.
Fixed Versions: 1.0.4

Impact

There is a possible XSS vulnerability in rails-html-sanitizer. The gem allows non-whitelisted
attributes to be present in sanitized output when input with specially-crafted HTML fragments,
and these attributes can lead to an XSS attack on target applications.

This issue is similar to CVE-2018-8048 in Loofah.

All users running an affected release should either upgrade or use one of the
workarounds immediately.

Releases

The FIXED releases are available at the normal locations.

Workarounds

There are no feasible workarounds for this issue.

Patches

To aid users who aren’t able to upgrade immediately we have provided patches for
the two supported release series. They are in git-am format and consist of a
single changeset.

• 1-0-sanitize_attributes.patch - Patch for 1.0 series

Credits

Thanks to Kaarlo Haikonen for reporting this issue and Mike Dalessio for providing the original fix in the Loofah gem.