The sanitize_css method 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 \n (newline) characters, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via crafted Cascading Style Sheets (CSS) token sequences.
lists.apple.com/archives/security-announce/2013/Jun/msg00000.html
lists.apple.com/archives/security-announce/2013/Oct/msg00006.html
lists.opensuse.org/opensuse-updates/2013-04/msg00072.html
lists.opensuse.org/opensuse-updates/2013-04/msg00073.html
lists.opensuse.org/opensuse-updates/2014-01/msg00013.html
rhn.redhat.com/errata/RHSA-2013-0698.html
rhn.redhat.com/errata/RHSA-2014-1863.html
support.apple.com/kb/HT5784
weblog.rubyonrails.org/2013/3/18/SEC-ANN-Rails-3-2-13-3-1-12-and-2-3-18-have-been-released/
groups.google.com/group/rubyonrails-security/msg/8ed835a97cdd1afd?dmode=source&output=gplain