Merge remote-tracking branch 'upstream/develop' into develop

Conflicts:
	system/helpers/form_helper.php

1 files changed, 60 insertions, 26 deletions

diff --git a/system/core/Security.php b/system/core/Security.php
index 70cf3e013..faa52d746 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -18,7 +18,7 @@
  *
  * @package		CodeIgniter
  * @author		EllisLab Dev Team
- * @copyright	Copyright (c) 2008 - 2013, EllisLab, Inc. (http://ellislab.com/)
+ * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 1.0
@@ -62,6 +62,19 @@ class CI_Security {
 	);
 
 	/**
+	 * HTML5 entities
+	 *
+	 * @var	array
+	 */
+	public $html5_entities = array(
+		':'	=> ':',
+		'('	=> '(',
+		')'	=> ')',
+		'&newline;'	=> "\n",
+		'&tab;'		=> "\t"
+	);
+
+	/**
 	 * XSS Hash
 	 *
 	 * Random Hash for protecting URLs.
@@ -117,7 +130,6 @@ class CI_Security {
 		'document.write'	=> '[removed]',
 		'.parentNode'		=> '[removed]',
 		'.innerHTML'		=> '[removed]',
-		'window.location'	=> '[removed]',
 		'-moz-binding'		=> '[removed]',
 		'<!--'				=> '&lt;!--',
 		'-->'				=> '--&gt;',
@@ -132,9 +144,13 @@ class CI_Security {
 	 */
 	protected $_never_allowed_regex = array(
 		'javascript\s*:',
+		'(document|(document\.)?window)\.(location|on\w*)',
 		'expression\s*(\(|&\#40;)', // CSS and IE
 		'vbscript\s*:', // IE, surprise!
-		'Redirect\s+302',
+		'wscript\s*:', // IE
+		'jscript\s*:', // IE
+		'vbs\s*:', // IE
+		'Redirect\s+30\d',
 		"([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
 	);
 
@@ -343,7 +359,11 @@ class CI_Security {
 		 *
 		 * Note: Use rawurldecode() so it does not remove plus signs
 		 */
-		$str = rawurldecode($str);
+		do
+		{
+			$str = rawurldecode($str);
+		}
+		while (preg_match('/%[0-9a-f]{2,}/i', $str));
 
 		/*
 		 * Convert character entities to ASCII
@@ -402,8 +422,9 @@ class CI_Security {
 		 * These words are compacted back to their correct state.
 		 */
 		$words = array(
-			'javascript', 'expression', 'vbscript', 'script', 'base64',
-			'applet', 'alert', 'document', 'write', 'cookie', 'window'
+			'javascript', 'expression', 'vbscript', 'jscript', 'wscript',
+			'vbs', 'script', 'base64', 'applet', 'alert', 'document',
+			'write', 'cookie', 'window', 'confirm', 'prompt'
 		);
 
 		foreach ($words as $word)
@@ -420,6 +441,12 @@ class CI_Security {
 		 * We used to do some version comparisons and use of stripos for PHP5,
 		 * but it is dog slow compared to these simplified non-capturing
 		 * preg_match(), especially if the pattern exists in the string
+		 *
+		 * Note: It was reported that not only space characters, but all in
+		 * the following pattern can be parsed as separators between a tag name
+		 * and its attributes: [\d\s"\'`;,\/\=\(\x00\x0B\x09\x0C]
+		 * ... however, remove_invisible_characters() above already strips the
+		 * hex-encoded ones, so we'll skip them below.
 		 */
 		do
 		{
@@ -427,12 +454,12 @@ class CI_Security {
 
 			if (preg_match('/<a/i', $str))
 			{
-				$str = preg_replace_callback('#<a\s+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
+				$str = preg_replace_callback('#<a[\s\d"\'`;/=,\(\\\\]+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
 			}
 
 			if (preg_match('/<img/i', $str))
 			{
-				$str = preg_replace_callback('#<img\s+([^>]*?)(?:\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
+				$str = preg_replace_callback('#<img[\s\d"\'`;/=,\(\\\\]+([^>]*?)(?:\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
 			}
 
 			if (preg_match('/script|xss/i', $str))
@@ -456,7 +483,7 @@ class CI_Security {
 		 * So this: <blink>
 		 * Becomes: &lt;blink&gt;
 		 */
-		$naughty = 'alert|applet|audio|basefont|base|behavior|bgsound|blink|body|embed|expression|form|frameset|frame|head|html|ilayer|iframe|input|isindex|layer|link|meta|object|plaintext|style|script|textarea|title|video|xml|xss';
+		$naughty = 'alert|prompt|confirm|applet|audio|basefont|base|behavior|bgsound|blink|body|embed|expression|form|frameset|frame|head|html|ilayer|iframe|input|button|select|isindex|layer|link|meta|keygen|object|plaintext|style|script|textarea|title|math|video|svg|xml|xss';
 		$str = preg_replace_callback('#<(/*\s*)('.$naughty.')([^><]*)([><]*)#is', array($this, '_sanitize_naughty_html'), $str);
 
 		/*
@@ -471,7 +498,7 @@ class CI_Security {
 		 * For example:	eval('some code')
 		 * Becomes:	eval&#40;'some code'&#41;
 		 */
-		$str = preg_replace('#(alert|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si',
+		$str = preg_replace('#(alert|prompt|confirm|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si',
 					'\\1\\2&#40;\\3&#41;',
 					$str);
 
@@ -551,13 +578,13 @@ class CI_Security {
 
 		do
 		{
-			$matches = $matches1 = 0;
+			$m1 = $m2 = 0;
 
+			$str = preg_replace('/(&#x0*[0-9a-f]{2,5})(?![0-9a-f;])/iS', '$1;', $str, -1, $m1);
+			$str = preg_replace('/(&#\d{2,4})(?![0-9;])/S', '$1;', $str, -1, $m2);
 			$str = html_entity_decode($str, ENT_COMPAT, $charset);
-			$str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str, -1, $matches);
-			$str = preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str, -1, $matches1);
 		}
-		while ($matches OR $matches1);
+		while ($m1 OR $m2);
 
 		return $str;
 	}
@@ -603,7 +630,7 @@ class CI_Security {
 	 */
 	public function strip_image_tags($str)
 	{
-		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+		return preg_replace(array('#<img[\s/]+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img[\s/]+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
 	}
 
 	// ----------------------------------------------------------------
@@ -648,8 +675,7 @@ class CI_Security {
 	 */
 	protected function _remove_evil_attributes($str, $is_image)
 	{
-		// All javascript event handlers (e.g. onload, onclick, onmouseover), style, and xmlns
-		$evil_attributes = array('on\w*', 'style', 'xmlns', 'formaction');
+		$evil_attributes = array('on\w*', 'style', 'xmlns', 'formaction', 'form', 'xlink:href');
 
 		if ($is_image === TRUE)
 		{
@@ -665,7 +691,7 @@ class CI_Security {
 			$attribs = array();
 
 			// find occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes)
-			preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', $str, $matches, PREG_SET_ORDER);
+			preg_match_all('/(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', $str, $matches, PREG_SET_ORDER);
 
 			foreach ($matches as $attr)
 			{
@@ -673,7 +699,7 @@ class CI_Security {
 			}
 
 			// 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('/(?<!\w)('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER);
 
 			foreach ($matches as $attr)
 			{
@@ -727,7 +753,7 @@ class CI_Security {
 	protected function _js_link_removal($match)
 	{
 		return str_replace($match[1],
-					preg_replace('#href=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
+					preg_replace('#href=.*?(?:(?:alert|prompt|confirm)(?:\(|&\#40;)|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
 							'',
 							$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
 					),
@@ -752,7 +778,7 @@ class CI_Security {
 	protected function _js_img_removal($match)
 	{
 		return str_replace($match[1],
-					preg_replace('#src=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
+					preg_replace('#src=.*?(?:(?:alert|prompt|confirm)(?:\(|&\#40;)|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
 							'',
 							$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
 					),
@@ -810,7 +836,14 @@ class CI_Security {
 	 */
 	protected function _decode_entity($match)
 	{
-		return $this->entity_decode($match[0], strtoupper(config_item('charset')));
+		// entity_decode() won't convert dangerous HTML5 entities
+		// (it could, but ENT_HTML5 is only available since PHP 5.4),
+		// so we'll do that here
+		return str_ireplace(
+			array_keys($this->html5_entities),
+			array_values($this->html5_entities),
+			$this->entity_decode($match[0], strtoupper(config_item('charset')))
+		);
 	}
 
 	// --------------------------------------------------------------------
@@ -837,14 +870,15 @@ class CI_Security {
 		 * Add a semicolon if missing.  We do this to enable
 		 * the conversion of entities to ASCII later.
 		 */
-		$str = preg_replace('#(&\#?[0-9a-z]{2,})([\x00-\x20])*;?#i', '\\1;\\2', $str);
+		$str = preg_replace('/(&#\d{2,4})(?![0-9;])/', '$1;', $str);
+		$str = preg_replace('/(&[a-z]{2,})(?![a-z;])/i', '$1;', $str);
 
 		/*
 		 * Validate UTF16 two byte encoding (x00)
 		 *
 		 * Just as above, adds a semicolon if missing.
 		 */
-		$str = preg_replace('#(&\#x?)([0-9A-F]+);?#i', '\\1\\2;', $str);
+		$str = preg_replace('/(&#x0*[0-9a-f]{2,5})(?![0-9a-f;])/i', '$1;', $str);
 
 		/*
 		 * Un-Protect GET variables in URLs
@@ -884,7 +918,7 @@ class CI_Security {
 	{
 		if ($this->_csrf_hash === '')
 		{
-			// If the cookie exists we will use it's value.
+			// If the cookie exists we will use its value.
 			// We don't necessarily want to regenerate it with
 			// each page load since a page could contain embedded
 			// sub-pages causing this feature to fail
@@ -894,7 +928,7 @@ class CI_Security {
 				return $this->_csrf_hash = $_COOKIE[$this->_csrf_cookie_name];
 			}
 
-			$this->_csrf_hash = md5(uniqid(rand(), TRUE));
+			$this->_csrf_hash = md5(uniqid(mt_rand(), TRUE));
 			$this->csrf_set_cookie();
 		}