Fix #3572: CI_Security::_remove_evil_attributes()

1 files changed, 6 insertions, 21 deletions

diff --git a/system/core/Security.php b/system/core/Security.php
index ccb141260..216f0e98b 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -784,30 +784,15 @@ class CI_Security {
 		}
 
 		do {
-			$count = 0;
-			$attribs = array();
+			$count = $temp_count = 0;
 
-			// find occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes)
-			preg_match_all('/(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', $str, $matches, PREG_SET_ORDER);
-
-			foreach ($matches as $attr)
-			{
-				$attribs[] = preg_quote($attr[0], '/');
-			}
+			// replace occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes)
+			$str = preg_replace('/(<[^>]+)(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', '$1[removed]', $str, -1, $temp_count);
+			$count += $temp_count;
 
 			// find occurrences of illegal attribute strings without quotes
-			preg_match_all('/(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER);
-
-			foreach ($matches as $attr)
-			{
-				$attribs[] = preg_quote($attr[0], '/');
-			}
-
-			// replace illegal attribute strings that are inside an html tag
-			if (count($attribs) > 0)
-			{
-				$str = preg_replace('/(<?)(\/?[^><]+?)([^A-Za-z<>\-])(.*?)('.implode('|', $attribs).')(.*?)([\s><]?)([><]*)/i', '$1$2 $4$6$7$8', $str, -1, $count);
-			}
+			$str = preg_replace('/(<[^>]+)(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', '$1[removed]', $str, -1, $temp_count);
+			$count += $temp_count;
 		}
 		while ($count);