The sanitize helper in lib/action_controller/vendor/html-scanner/html/sanitizer.rb
in the Action Pack component in Ruby on Rails before 2.3.18, 3.0.x and 3.1.x before 3.1.12, and 3.2.x before 3.2.13 does not properly handle encoded :
(colon) characters in URLs, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted scheme name, as demonstrated by including a :
sequence.
{ "nvd_published_at": "2013-03-19T22:55:01Z", "cwe_ids": [ "CWE-79" ], "severity": "MODERATE", "github_reviewed": true, "github_reviewed_at": "2020-06-16T21:42:30Z" }