Cross-site scripting (XSS) vulnerability in the RedCloth library 4.2.9 for Ruby and earlier allows remote attackers to inject arbitrary web script or HTML via a javascript: URI.
https://gist.github.com/co3k/75b3cb416c342aa1414c
http://www.debian.org/security/2015/dsa-3168
http://jgarber.lighthouseapp.com/projects/13054-redcloth/tickets/243-xss