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Fix again for Internet Explorer's stupidity of decoding characters, then
executing it blindly. This code was fixed originally, but apparently some
how didn't work right. I checked on HastyMail and did a file comparision,
and noticed that one version of the same filter doesn't use \W... on removal
of that in the regex, the function seemed to correctly strip out bad functions

See http://www.securityfocus.com/archive/1/340118 for further information.

jangliss 21 years ago
parent
commit
61fe1c1a2e
1 changed files with 11 additions and 9 deletions
  1. 11 9
      functions/mime.php

+ 11 - 9
functions/mime.php

@@ -850,6 +850,7 @@ function sq_unbackslash($attvalue){
     /**
      * Remove any backslashes. See if there are any first.
      */
+
     if (strstr($attvalue, '\\') !== false){
         $attvalue = stripslashes($attvalue);
     }
@@ -1282,13 +1283,14 @@ function sq_getnxtag($body, $offset){
  * @param  $attvalue A string to run entity check against.
  * @return           Translated value.
  */
+
 function sq_deent($attvalue){
     $me = 'sq_deent';
     /**
      * See if we have to run the checks first. All entities must start
      * with "&".
      */
-    if (strpos($attvalue, "&") === false){
+    if (strpos($attvalue, '&') === false){
         return $attvalue;
     }
     /**
@@ -1299,22 +1301,22 @@ function sq_deent($attvalue){
      * Leave " in, as it can mess us up.
      */
     $trans = array_flip($trans);
-    unset($trans{"""});
+    unset($trans{'"'});
     while (list($ent, $val) = each($trans)){
-        $attvalue = preg_replace("/$ent*(\W)/si", "$val\\1", $attvalue);
+        $attvalue = preg_replace('/' . $ent . '*/si', $val, $attvalue);
     }
     /**
      * Now translate numbered entities from 1 to 255 if needed.
      */
-    if (strpos($attvalue, "#") !== false){
+    if (strpos($attvalue, '#') !== false){
         $omit = Array(34, 39);
-        for ($asc=1; $asc<256; $asc++){
+        for ($asc = 256; $asc >= 0; $asc--){
             if (!in_array($asc, $omit)){
                 $chr = chr($asc);
-                $attvalue = preg_replace("/\&#0*$asc;*(\D)/si", "$chr\\1",
-                                         $attvalue);
-                $attvalue = preg_replace("/\&#x0*".dechex($asc).";*(\W)/si",
-                                         "$chr\\1", $attvalue);
+                $octrule = '/\&#0*' . $asc . ';*/si';
+                $hexrule = '/\&#x0*' . dechex($asc) . ';*/si';
+                $attvalue = preg_replace($octrule, $chr, $attvalue);
+                $attvalue = preg_replace($hexrule, $chr, $attvalue);
             }
         }
     }