Updating XSS cleaning to better handle base64 encoded attributes.
diff --git a/system/core/Security.php b/system/core/Security.php
index ac39ce9..6574663 100755
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -99,7 +99,8 @@
'javascript\s*:',
'expression\s*(\(|&\#40;)', // CSS and IE
'vbscript\s*:', // IE, surprise!
- 'Redirect\s+302'
+ 'Redirect\s+302',
+ "([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
);
public function __construct()
@@ -362,7 +363,7 @@
* These words are compacted back to their correct state.
*/
$words = array(
- 'javascript', 'expression', 'vbscript', 'script',
+ 'javascript', 'expression', 'vbscript', 'script', 'base64',
'applet', 'alert', 'document', 'write', 'cookie', 'window'
);
@@ -602,10 +603,11 @@
$attribs = array();
// find occurrences of illegal attribute strings without quotes
- preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s]*)/is', $str, $matches, PREG_SET_ORDER);
+ preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER);
foreach ($matches as $attr)
{
+
$attribs[] = preg_quote($attr[0], '/');
}
@@ -620,7 +622,7 @@
// 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$5', $str, -1, $count);
+ $str = preg_replace("/<(\/?[^><]+?)([^A-Za-z<>\-])(.*?)(".implode('|', $attribs).")(.*?)([\s><])([><]*)/i", '<$1 $3$5$6$7', $str, -1, $count);
}
} while ($count);
@@ -661,7 +663,7 @@
protected function _js_link_removal($match)
{
return str_replace($match[1],
- preg_replace('#href=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
+ preg_replace('#href=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
'',
$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
),
@@ -801,7 +803,7 @@
foreach ($this->_never_allowed_regex as $regex)
{
- $str = preg_replace('#'.$regex.'#i', '[removed]', $str);
+ $str = preg_replace('#'.$regex.'#is', '[removed]', $str);
}
return $str;