From e7d1a80a800f6f08c0a683d2be04b0db2a1f6523 Mon Sep 17 00:00:00 2001
From: Aleksander Machniak <alec@alec.pl>
Date: Fri, 06 Nov 2015 02:37:07 -0500
Subject: [PATCH] Fix HTML sanitizer to skip <!-- node type X --> in output (#1490583)
---
program/lib/Roundcube/rcube_washtml.php | 126 +++++++++++++++++++++++++++---------------
1 files changed, 81 insertions(+), 45 deletions(-)
diff --git a/program/lib/Roundcube/rcube_washtml.php b/program/lib/Roundcube/rcube_washtml.php
index 5a5b3dc..0ce6cb3 100644
--- a/program/lib/Roundcube/rcube_washtml.php
+++ b/program/lib/Roundcube/rcube_washtml.php
@@ -171,7 +171,7 @@
*/
private function wash_style($style)
{
- $s = '';
+ $result = array();
foreach (explode(';', $style) as $declaration) {
if (preg_match('/^\s*([a-z\-]+)\s*:\s*(.*)\s*$/i', $declaration, $match)) {
@@ -179,54 +179,48 @@
$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);
}
/**
@@ -249,8 +243,8 @@
$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
if (($src = $this->config['cid_map'][$value])
@@ -283,10 +277,12 @@
/**
* The main loop that recurse on a node tree.
- * It output only allowed tags with allowed attributes
- * and allowed inline styles
+ * It output only allowed tags with allowed attributes and allowed inline styles
+ *
+ * @param DOMNode $node HTML element
+ * @param int $level Recurrence level (safe initial value found empirically)
*/
- private function dumpHtml($node, $level = 0)
+ private function dumpHtml($node, $level = 20)
{
if (!$node->hasChildNodes()) {
return '';
@@ -310,7 +306,7 @@
$dump = '';
do {
- switch($node->nodeType) {
+ switch ($node->nodeType) {
case XML_ELEMENT_NODE: //Check element
$tagName = strtolower($node->tagName);
if ($callback = $this->handlers[$tagName]) {
@@ -342,14 +338,9 @@
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;
}
@@ -460,7 +451,7 @@
// 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);
@@ -576,4 +567,49 @@
}
}
}
+
+ /**
+ * 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;
+ }
}
--
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