Ticket #6583: bug6583.patch

kses.php

@@ -271 +271 @@
                 'u' => array(),
                 'ul' => array (
                         'class' => array (),
-                        'style' => array (), 
+                        'style' => array (),
                         'type' => array ()),
                 'ol' => array (
                         'class' => array (),
                         'start' => array (),
-                        'style' => array (), 
+                        'style' => array (),
                         'type' => array ()),
                 'var' => array ());
         /**
@@ -896 +896 @@
 
         $string = preg_replace('/&([A-Za-z][A-Za-z0-9]{0,19});/', '&\\1;', $string);
         $string = preg_replace_callback('/&#0*([0-9]{1,5});/', create_function('$matches', 'return wp_kses_normalize_entities2($matches[1]);'), $string);
-        $string = preg_replace('/&#([Xx])0*(([0-9A-Fa-f]{2}){1,2});/', '&#\\1\\2;', $string);
+        $string = preg_replace_callback('/&#([Xx])0*(([0-9A-Fa-f]{2}){1,2});/', create_function('$matches', 'return wp_kses_normalize_entities3($matches[2]);'), $string);
 
         return $string;
 }
@@ -913 +913 @@
  * @return string Correctly encoded entity
  */
 function wp_kses_normalize_entities2($i) {
-        return (($i > 65535) ? "&#$i;" : "&#$i;");
+        return ( (!valid_unicode($i)) || ($i > 65535) ? "&#$i;" : "&#$i;");
 }
 
 /**
+ * wp_kses_normalize_entities3() - Callback for wp_kses_normalize_entities() for regular expression
+ *
+ * This function helps wp_kses_normalize_entities() to only accept valid Unicode numeric entities
+ * in hex form.
+ *
+ * @param string $h Hex string of encoded entity
+ * @return string Correctly encoded entity
+ */
+function wp_kses_normalize_entities3($hexchars) {
+        return ( (!valid_unicode(hexdec($hexchars))) ? "&#x$hexchars;" : "&#x$hexchars;");
+}
+
+/**
+ * valid_unicode() - Helper function to determine if a Unicode value is valid.
+ *
+ * @param int $i Unicode value
+ * @return bool true if the value was a valid Unicode number
+ */
+function valid_unicode($i) {
+        return ( $i == 0x9 || $i == 0xa || $i == 0xd ||
+                        ($i >= 0x20 && $i <= 0xd7ff) ||
+                        ($i >= 0xe000 && $i <= 0xfffd) ||
+                        ($i >= 0x10000 && $i <= 0x10ffff) );
+}
+
+/**
  * wp_kses_decode_entities() - Convert all entities to their character counterparts.
  *
  * This function decodes numeric HTML entities (&#65; and &#x41;). It