# HG changeset patch
# User cmlenz
# Date 1183494547 0
# Node ID 0d98569eaced0e00e9ceb92240d694ebaeba1fcc
# Parent  489a47873950f98a8968b22441f01e4879294813
The HTML sanitizer now strips any CSS comments in style attributes, which could previously be used to hide malicious property values.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -32,6 +32,8 @@
    it is not available for use through configuration files.
  * The I18n filter now extracts messages from gettext functions even inside
    ignored tags (ticket #132).
+ * The HTML sanitizer now strips any CSS comments in style attributes, which
+   could previously be used to hide malicious property values.
 
 
 Version 0.4.2
diff --git a/genshi/filters/html.py b/genshi/filters/html.py
--- a/genshi/filters/html.py
+++ b/genshi/filters/html.py
@@ -285,7 +285,9 @@
                     elif attr == 'style':
                         # Remove dangerous CSS declarations from inline styles
                         decls = []
-                        value = self._replace_unicode_escapes(value)
+                        value = self._strip_css_comments(
+                            self._replace_unicode_escapes(value)
+                        )
                         for decl in filter(None, value.split(';')):
                             is_evil = False
                             if 'expression' in decl:
@@ -322,3 +324,8 @@
         def _repl(match):
             return unichr(int(match.group(1), 16))
         return self._UNICODE_ESCAPE(_repl, self._NORMALIZE_NEWLINES('\n', text))
+
+    _CSS_COMMENTS = re.compile(r'/\*.*?\*/').sub
+
+    def _strip_css_comments(self, text):
+        return self._CSS_COMMENTS('', text)
diff --git a/genshi/filters/tests/html.py b/genshi/filters/tests/html.py
--- a/genshi/filters/tests/html.py
+++ b/genshi/filters/tests/html.py
@@ -332,6 +332,8 @@
         # IE expressions in CSS not allowed
         html = HTML('<DIV STYLE=\'width: expression(alert("foo"));\'>')
         self.assertEquals(u'<div/>', unicode(html | sanitizer))
+        html = HTML('<DIV STYLE=\'width: e/**/xpression(alert("foo"));\'>')
+        self.assertEquals(u'<div/>', unicode(html | sanitizer))
         html = HTML('<DIV STYLE=\'background: url(javascript:alert("foo"));'
                                  'color: #fff\'>')
         self.assertEquals(u'<div style="color: #fff"/>',