note 33277 modified in function.strip-tags by vrana

To fix the <scr<script></script>ipt> bug, I'm going to use the following function for my upcoming forum project: function realsafehtml($str) { // Don't do anything if there's no difference or if the original string is empty $oldstr = ""; while($str != $oldstr) // Loop until it got no more effect { $oldstr = $str; //nuke script and header tags and anything inbetween $str = preg_replace("'<script[^>]*>.*</script>'siU", "", $str); $str = preg_replace("'<head[^>]*>.*</head>'siU", "", $str); //listed of tags that will not be striped but whose attributes will be $allowed = "br|b|i|p|u|a|center|hr"; //start nuking those suckers. don you just love MS Word's HTML? $str = preg_replace("/<((?!\/?($allowed)\b)[^>]*>)/xis", "", $str); $str = preg_replace("/<($allowed).*?>/i", "<\\1>", $str); } return $str; } It's obviously more expensive than the original function, but also a lot more secure :) I hope this can help someone - didn't test it much yet, though. --was-- To fix the <scr<script></script>ipt> bug, I'm going to use the following function for my upcoming forum project: function realsafehtml($str) { // Don't do anything if there's no difference or if the original string is empty $oldstr = ""; while($str != $oldstr) // Loop until it got no more effect { $oldstr = $str; //nuke script and header tags and anything inbetween $str = preg_replace("'<script[^>]*>.*</script>'siU", "", $str); $str = preg_replace("'<head[^>]*>.*</head>'siU", "", $str); //listed of tags that will not be striped but whose attributes will be $allowed = "br|b|i|p|u|a|center|hr"; //start nuking those suckers. don you just love MS Word's HTML? $str = preg_replace("/<((?!\/?($allowed)\b)[^>]*>)/xis", "", $str); $str = preg_replace("/<($allowed).*?>/i", "<\\1>", $str); } return $str; } It's obviously more expensive than the original function, but also a lot more secure :) I hope this can help someone - didn't test it much yet, though. [ Editor note: use U (ungreedy) pattern modified to not strip inner contents. ] http://www.php.net/manual/en/function.strip-tags.php