From b6d9e320f1a6397e422c73480347dd1a0864bcf4 Mon Sep 17 00:00:00 2001
From: Charlie Somerville <charlie@charliesomerville.com>
Date: Wed, 13 Feb 2013 09:09:53 +1100
Subject: [PATCH] fix incorrect ^$ usage leading to XSS in sanitize_css

---
 .../lib/action_controller/vendor/html-scanner/html/sanitizer.rb     | 6 +++---
 actionpack/test/template/html-scanner/sanitizer_test.rb             | 5 +++++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb b/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb
index af06bff..02eea58 100644
--- a/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb
+++ b/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb
@@ -110,8 +110,8 @@ module HTML
       style = style.to_s.gsub(/url\s*\(\s*[^\s)]+?\s*\)\s*/, ' ')
 
       # gauntlet
-      if style !~ /^([:,;#%.\sa-zA-Z0-9!]|\w-\w|\'[\s\w]+\'|\"[\s\w]+\"|\([\d,\s]+\))*$/ ||
-          style !~ /^(\s*[-\w]+\s*:\s*[^:;]*(;|$)\s*)*$/
+      if style !~ /\A([:,;#%.\sa-zA-Z0-9!]|\w-\w|\'[\s\w]+\'|\"[\s\w]+\"|\([\d,\s]+\))*\z/ ||
+          style !~ /\A(\s*[-\w]+\s*:\s*[^:;]*(;|$)\s*)*\z/
         return ''
       end
 
@@ -122,7 +122,7 @@ module HTML
         elsif shorthand_css_properties.include?(prop.split('-')[0].downcase)
           unless val.split().any? do |keyword|
             !allowed_css_keywords.include?(keyword) &&
-              keyword !~ /^(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)$/
+              keyword !~ /\A(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)\z/
           end
             clean << prop + ': ' + val + ';'
           end
diff --git a/actionpack/test/template/html-scanner/sanitizer_test.rb b/actionpack/test/template/html-scanner/sanitizer_test.rb
index 844484e..4e2ad4e 100644
--- a/actionpack/test/template/html-scanner/sanitizer_test.rb
+++ b/actionpack/test/template/html-scanner/sanitizer_test.rb
@@ -256,6 +256,11 @@ class SanitizerTest < ActionController::TestCase
     assert_equal '', sanitize_css(raw)
   end
 
+  def test_should_sanitize_across_newlines
+    raw = %(\nwidth:\nexpression(alert('XSS'));\n)
+    assert_equal '', sanitize_css(raw)
+  end
+
   def test_should_sanitize_img_vbscript
     assert_sanitized %(<img src='vbscript:msgbox("XSS")' />), '<img />'
   end
-- 
1.8.1.1