From c7c09f85d9ccab83f720d1f938035884b9db5d6a Mon Sep 17 00:00:00 2001 From: Aleksander Machniak <alec@alec.pl> Date: Thu, 05 Nov 2015 02:48:34 -0500 Subject: [PATCH] Fix HTML sanitizer to skip <!-- node type X --> in output (#1490583) --- program/lib/Roundcube/rcube_washtml.php | 148 ++++++++++++++++++++++++++++++++---------------- 1 files changed, 98 insertions(+), 50 deletions(-) diff --git a/program/lib/Roundcube/rcube_washtml.php b/program/lib/Roundcube/rcube_washtml.php index e9fec54..9f23f8e 100644 --- a/program/lib/Roundcube/rcube_washtml.php +++ b/program/lib/Roundcube/rcube_washtml.php @@ -1,6 +1,6 @@ <?php -/** +/* +-----------------------------------------------------------------------+ | This file is part of the Roundcube Webmail client | | Copyright (C) 2008-2012, The Roundcube Dev Team | @@ -18,7 +18,7 @@ +-----------------------------------------------------------------------+ */ -/** +/* * Washtml, a HTML sanityzer. * * Copyright (c) 2007 Frederic Motte <fmotte@ubixis.com> @@ -95,6 +95,7 @@ 'ins', 'label', 'legend', 'li', 'map', 'menu', 'nobr', 'ol', 'p', 'pre', 'q', 's', 'samp', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'table', 'tbody', 'td', 'tfoot', 'th', 'thead', 'tr', 'tt', 'u', 'ul', 'var', 'wbr', 'img', + 'video', 'source', // form elements 'button', 'input', 'textarea', 'select', 'option', 'optgroup' ); @@ -171,7 +172,10 @@ */ private function wash_style($style) { - $s = ''; + $result = array(); + + // Remove unwanted white-space characters so regular expressions below work better + $style = preg_replace('/[\n\r\s\t]+/', ' ', $style); foreach (explode(';', $style) as $declaration) { if (preg_match('/^\s*([a-z\-]+)\s*:\s*(.*)\s*$/i', $declaration, $match)) { @@ -179,54 +183,48 @@ $str = $match[2]; $value = ''; - while (sizeof($str) > 0 && - preg_match('/^(url\(\s*[\'"]?([^\'"\)]*)[\'"]?\s*\)'./*1,2*/ - '|rgb\(\s*[0-9]+\s*,\s*[0-9]+\s*,\s*[0-9]+\s*\)'. - '|-?[0-9.]+\s*(em|ex|px|cm|mm|in|pt|pc|deg|rad|grad|ms|s|hz|khz|%)?'. - '|#[0-9a-f]{3,6}'. - '|[a-z0-9"\', -]+'. - ')\s*/i', $str, $match) - ) { - if ($match[2]) { - if (($src = $this->config['cid_map'][$match[2]]) - || ($src = $this->config['cid_map'][$this->config['base_url'].$match[2]]) - ) { - $value .= ' url('.htmlspecialchars($src, ENT_QUOTES) . ')'; - } - else if (preg_match('!^(https?:)?//[a-z0-9/._+-]+$!i', $match[2], $url)) { - if ($this->config['allow_remote']) { - $value .= ' url('.htmlspecialchars($url[0], ENT_QUOTES).')'; + foreach ($this->explode_style($str) as $val) { + if (preg_match('/^url\(/i', $val)) { + if (preg_match('/^url\(\s*[\'"]?([^\'"\)]*)[\'"]?\s*\)/iu', $val, $match)) { + $url = $match[1]; + if (($src = $this->config['cid_map'][$url]) + || ($src = $this->config['cid_map'][$this->config['base_url'].$url]) + ) { + $value .= ' url('.htmlspecialchars($src, ENT_QUOTES) . ')'; } - else { - $this->extlinks = true; + else if (preg_match('!^(https?:)?//[a-z0-9/._+-]+$!i', $url, $m)) { + if ($this->config['allow_remote']) { + $value .= ' url('.htmlspecialchars($m[0], ENT_QUOTES).')'; + } + else { + $this->extlinks = true; + } } - } - else if (preg_match('/^data:.+/i', $match[2])) { // RFC2397 - $value .= ' url('.htmlspecialchars($match[2], ENT_QUOTES).')'; + else if (preg_match('/^data:.+/i', $url)) { // RFC2397 + $value .= ' url('.htmlspecialchars($url, ENT_QUOTES).')'; + } } } - else { + else if (!preg_match('/^(behavior|expression)/i', $val)) { // whitelist ? - $value .= ' ' . $match[0]; + $value .= ' ' . $val; // #1488535: Fix size units, so width:800 would be changed to width:800px - if (preg_match('/(left|right|top|bottom|width|height)/i', $cssid) - && preg_match('/^[0-9]+$/', $match[0]) + if (preg_match('/^(left|right|top|bottom|width|height)/i', $cssid) + && preg_match('/^[0-9]+$/', $val) ) { $value .= 'px'; } } - - $str = substr($str, strlen($match[0])); } if (isset($value[0])) { - $s .= ($s?' ':'') . $cssid . ':' . $value . ';'; + $result[] = $cssid . ':' . $value; } } } - return $s; + return implode('; ', $result); } /** @@ -249,10 +247,13 @@ $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"'; } else if ($key == 'style' && ($style = $this->wash_style($value))) { - $quot = strpos($style, '"') !== false ? "'" : '"'; - $t .= ' style=' . $quot . $style . $quot; + // replace double quotes to prevent syntax error and XSS issues (#1490227) + $t .= ' style="' . str_replace('"', '"', $style) . '"'; } - else if ($key == 'background' || ($key == 'src' && strtolower($node->tagName) == 'img')) { //check tagName anyway + else if ($key == 'background' + || ($key == 'src' && preg_match('/^(img|source)$/i', $node->tagName)) + || ($key == 'poster' && strtolower($node->tagName) == 'video') + ) { if (($src = $this->config['cid_map'][$value]) || ($src = $this->config['cid_map'][$this->config['base_url'].$value]) ) { @@ -312,7 +313,7 @@ $dump = ''; do { - switch($node->nodeType) { + switch ($node->nodeType) { case XML_ELEMENT_NODE: //Check element $tagName = strtolower($node->tagName); if ($callback = $this->handlers[$tagName]) { @@ -344,14 +345,9 @@ case XML_HTML_DOCUMENT_NODE: $dump .= $this->dumpHtml($node, $level); break; - - case XML_DOCUMENT_TYPE_NODE: - break; - - default: - $dump .= '<!-- node type ' . $node->nodeType . ' -->'; } - } while($node = $node->nextSibling); + } + while($node = $node->nextSibling); return $dump; } @@ -380,7 +376,7 @@ $this->max_nesting_level = (int) @ini_get('xdebug.max_nesting_level'); // Use optimizations if supported - if (version_compare(PHP_VERSION, '5.4.0', '>=')) { + if (PHP_VERSION_ID >= 50400) { @$node->loadHTML($html, LIBXML_PARSEHUGE | LIBXML_COMPACT); } else { @@ -405,14 +401,21 @@ { // special replacements (not properly handled by washtml class) $html_search = array( - '/(<\/nobr>)(\s+)(<nobr>)/i', // space(s) between <NOBR> - '/<title[^>]*>[^<]*<\/title>/i', // PHP bug #32547 workaround: remove title tag - '/^(\0\0\xFE\xFF|\xFF\xFE\0\0|\xFE\xFF|\xFF\xFE|\xEF\xBB\xBF)/', // byte-order mark (only outlook?) - '/<html\s[^>]+>/i', // washtml/DOMDocument cannot handle xml namespaces + // space(s) between <NOBR> + '/(<\/nobr>)(\s+)(<nobr>)/i', + // PHP bug #32547 workaround: remove title tag + '/<title[^>]*>[^<]*<\/title>/i', + // remove <!doctype> before BOM (#1490291) + '/<\!doctype[^>]+>[^<]*/im', + // byte-order mark (only outlook?) + '/^(\0\0\xFE\xFF|\xFF\xFE\0\0|\xFE\xFF|\xFF\xFE|\xEF\xBB\xBF)/', + // washtml/DOMDocument cannot handle xml namespaces + '/<html\s[^>]+>/i', ); $html_replace = array( '\\1'.' '.'\\3', + '', '', '', '<html>', @@ -462,7 +465,7 @@ // Remove invalid HTML comments (#1487759) // Don't remove valid conditional comments // Don't remove MSOutlook (<!-->) conditional comments (#1489004) - $html = preg_replace('/<!--[^->\[\n]+>/', '', $html); + $html = preg_replace('/<!--[^-<>\[\n]+>/', '', $html); // fix broken nested lists self::fix_broken_lists($html); @@ -578,4 +581,49 @@ } } } + + /** + * Explode css style value + */ + protected function explode_style($style) + { + $style = trim($style); + + // first remove comments + $pos = 0; + while (($pos = strpos($style, '/*', $pos)) !== false) { + $end = strpos($style, '*/', $pos+2); + + if ($end === false) { + $style = substr($style, 0, $pos); + } + else { + $style = substr_replace($style, '', $pos, $end - $pos + 2); + } + } + + $strlen = strlen($style); + $result = array(); + + // explode value + for ($p=$i=0; $i < $strlen; $i++) { + if (($style[$i] == "\"" || $style[$i] == "'") && $style[$i-1] != "\\") { + if ($q == $style[$i]) { + $q = false; + } + else if (!$q) { + $q = $style[$i]; + } + } + + if (!$q && $style[$i] == ' ' && !preg_match('/[,\(]/', $style[$i-1])) { + $result[] = substr($style, $p, $i - $p); + $p = $i + 1; + } + } + + $result[] = (string) substr($style, $p); + + return $result; + } } -- Gitblit v1.9.1