From f50cc72cbbe443dff8a5daa34ece6cafe8757089 Mon Sep 17 00:00:00 2001
From: alecpl <alec@alec.pl>
Date: Fri, 12 Dec 2008 08:02:33 +0000
Subject: #1485618: fix code injection vulnerability

---
 program/lib/html2text.php | 69 +++++++++++++++++++++++++++++++++++++----------
 1 file changed, 55 insertions(+), 14 deletions(-)

(limited to 'program')

diff --git a/program/lib/html2text.php b/program/lib/html2text.php
index 938dfecfe..d298ee2e4 100644
--- a/program/lib/html2text.php
+++ b/program/lib/html2text.php
@@ -149,25 +149,18 @@ class html2text
         '/<script[^>]*>.*?<\/script>/i',         // <script>s -- which strip_tags supposedly has problems with
         '/<style[^>]*>.*?<\/style>/i',           // <style>s -- which strip_tags supposedly has problems with
         //'/<!-- .* -->/',                         // Comments -- which strip_tags might have problem a with
-        '/<h[123][^>]*>(.*?)<\/h[123]>/ie',      // H1 - H3
-        '/<h[456][^>]*>(.*?)<\/h[456]>/ie',      // H4 - H6
         '/<p[^>]*>/i',                           // <P>
         '/<br[^>]*>/i',                          // <br>
-        '/<b[^>]*>(.*?)<\/b>/ie',                // <b>
-        '/<strong[^>]*>(.*?)<\/strong>/ie',      // <strong>
         '/<i[^>]*>(.*?)<\/i>/i',                 // <i>
         '/<em[^>]*>(.*?)<\/em>/i',               // <em>
         '/(<ul[^>]*>|<\/ul>)/i',                 // <ul> and </ul>
         '/(<ol[^>]*>|<\/ol>)/i',                 // <ol> and </ol>
         '/<li[^>]*>(.*?)<\/li>/i',               // <li> and </li>
         '/<li[^>]*>/i',                          // <li>
-        '/<a [^>]*href=("|\')([^"\']+)\1[^>]*>(.*?)<\/a>/ie',
-                                                 // <a href="">
         '/<hr[^>]*>/i',                          // <hr>
         '/(<table[^>]*>|<\/table>)/i',           // <table> and </table>
         '/(<tr[^>]*>|<\/tr>)/i',                 // <tr> and </tr>
         '/<td[^>]*>(.*?)<\/td>/i',               // <td> and </td>
-        '/<th[^>]*>(.*?)<\/th>/ie',              // <th> and </th>
         '/&(nbsp|#160);/i',                      // Non-breaking space
         '/&(quot|rdquo|ldquo|#8220|#8221|#147|#148);/i',
 		                                         // Double quotes
@@ -201,25 +194,18 @@ class html2text
         '',                                     // <script>s -- which strip_tags supposedly has problems with
         '',                                     // <style>s -- which strip_tags supposedly has problems with
         //'',                                     // Comments -- which strip_tags might have problem a with
-        "strtoupper(\"\n\n\\1\n\n\")",          // H1 - H3
-        "ucwords(\"\n\n\\1\n\")",             // H4 - H6
         "\n\n",                               // <P>
         "\n",                                   // <br>
-        'strtoupper("\\1")',                    // <b>
-        'strtoupper("\\1")',                    // <strong>
         '_\\1_',                                // <i>
         '_\\1_',                                // <em>
         "\n\n",                                 // <ul> and </ul>
         "\n\n",                                 // <ol> and </ol>
         "\t* \\1\n",                            // <li> and </li>
         "\n\t* ",                               // <li>
-    	'$this->_build_link_list("\\2", "\\3")',
-    	                                	// <a href="">
     	"\n-------------------------\n",        // <hr>
     	"\n\n",                                 // <table> and </table>
         "\n",                                   // <tr> and </tr>
         "\t\t\\1\n",                            // <td> and </td>
-        "strtoupper(\"\t\t\\1\n\")",            // <th> and </th>
         ' ',                                    // Non-breaking space
         '"',                                    // Double quotes
         "'",                                    // Single quotes
@@ -238,6 +224,22 @@ class html2text
         ' '                                     // Runs of spaces, post-handling
     );
 
+    /**
+     *  List of preg* regular expression patterns to search for
+     *  and replace using callback function.
+     *
+     *  @var array $callback_search
+     *  @access public
+     */
+    var $callback_search = array(
+        '/<(h)[123456][^>]*>(.*?)<\/h[123456]>/i', // H1 - H3
+        '/<(b)[^>]*>(.*?)<\/b>/i',                 // <b>
+        '/<(strong)[^>]*>(.*?)<\/strong>/i',       // <strong>
+        '/<(a) [^>]*href=("|\')([^"\']+)\2[^>]*>(.*?)<\/a>/i',
+                                                   // <a href="">
+        '/<(th)[^>]*>(.*?)<\/th>/i',               // <th> and </th>
+    );
+
    /**
     *  List of preg* regular expression patterns to search for in PRE body,
     *  used in conjunction with $pre_replace.
@@ -471,6 +473,7 @@ class html2text
 
         // Run our defined search-and-replace
         $text = preg_replace($this->search, $this->replace, $text);
+        $text = preg_replace_callback($this->callback_search, array('html2text', '_preg_callback'), $text);
 
         // Strip any other HTML tags
         $text = strip_tags($text, $this->allowed_tags);
@@ -549,6 +552,44 @@ class html2text
 	    $text = preg_replace('/<pre[^>]*>.*<\/pre>/ismU', '<div><br>' . $result . '<br></div>', $text, 1);
 	}
     }
+
+    /**
+     *  Callback function for preg_replace_callback use.
+     *
+     *  @param  array PREG matches
+     *  @return string
+     *  @access private
+     */
+    function _preg_callback($matches)
+    {
+	switch($matches[1])
+	{
+	    case 'b':
+	    case 'strong':
+		return $this->_strtoupper($matches[2]);
+	    case 'hr':
+		return $this->_strtoupper("\t\t". $matches[2] ."\n");
+	    case 'h':
+		return $this->_strtoupper("\n\n". $matches[2] ."\n\n");
+	    case 'a':
+    	        return $this->_build_link_list($matches[3], $matches[4]);
+	}
+    }
+    
+    /**
+     *  Strtoupper multibyte wrapper function
+     *
+     *  @param  string
+     *  @return string
+     *  @access private
+     */
+    function _strtoupper($str)
+    {
+	if (function_exists('mb_strtoupper'))
+    	    return mb_strtoupper($str);
+    	else
+	    return strtoupper($str);
+    }
 }
 
 ?>
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