githubFork/roundcubemail.git

Fix XSS issue in SVG images handling (#1490625)

Aleksander Machniak

2016-01-06 7bbefdb63b12e2344cf1cb87aeb6e3933b4063e0

commit \| author \| age
4e17e6	1	<?php
T	2
	3	/*
	4	+-----------------------------------------------------------------------+
	5	\| program/steps/mail/get.inc \|
	6	\| \|
e019f2	7	\| This file is part of the Roundcube Webmail client \|
c97625	8	\| Copyright (C) 2005-2013, The Roundcube Dev Team \|
7fe381	9	\| \|
T	10	\| Licensed under the GNU General Public License version 3 or \|
	11	\| any later version with exceptions for skins & plugins. \|
	12	\| See the README file for a full license statement. \|
4e17e6	13	\| \|
T	14	\| PURPOSE: \|
	15	\| Delivering a specific part of a mail message \|
	16	\| \|
	17	+-----------------------------------------------------------------------+
	18	\| Author: Thomas Bruederli <roundcube@gmail.com> \|
	19	+-----------------------------------------------------------------------+
	20	*/
	21
	22
	23	// show loading page
8fa58e	24	if (!empty($_GET['_preload'])) {
c14c21	25	$_get = $_GET + array('_mimewarning' => 1, '_embed' => 1);
TB	26	unset($_get['_preload']);
	27	$url = $RCMAIL->url($_get);
c97625	28	$message = $RCMAIL->gettext('loadingdata');
4e17e6	29
c97625	30	header('Content-Type: text/html; charset=' . RCUBE_CHARSET);
AM	31	print "<html>\n<head>\n"
6b2b2e	32	. '<meta http-equiv="refresh" content="0; url='.rcube::Q($url).'">' . "\n"
AM	33	. '<meta http-equiv="content-type" content="text/html; charset='.RCUBE_CHARSET.'">' . "\n"
3e8b11	34	. "</head>\n<body>\n$message\n</body>\n</html>";
c97625	35	exit;
8fa58e	36	}
4e17e6	37
d51c93	38	ob_end_clean();
4e17e6	39
1ef403	40
4e17e6	41	// similar code as in program/steps/mail/show.inc
8fa58e	42	if (!empty($_GET['_uid'])) {
c97625	43	$uid = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_GET);
AM	44	$RCMAIL->config->set('prefer_html', true);
	45	$MESSAGE = new rcube_message($uid);
8fa58e	46	}
4bfe4e	47
AM	48	// check connection status
	49	check_storage_status();
4e17e6	50
6b2b2e	51	$part_id = rcube_utils::get_input_value('_part', rcube_utils::INPUT_GPC);
eaf383	52
4e17e6	53	// show part page
8fa58e	54	if (!empty($_GET['_frame'])) {
c97625	55	if ($part_id && ($part = $MESSAGE->mime_parts[$part_id])) {
AM	56	$filename = rcmail_attachment_name($part);
	57	$OUTPUT->set_pagetitle($filename);
	58	}
b6da0b	59
c97625	60	// register UI objects
AM	61	$OUTPUT->add_handlers(array(
	62	'messagepartframe' => 'rcmail_message_part_frame',
	63	'messagepartcontrols' => 'rcmail_message_part_controls',
	64	));
eaf383	65
c97625	66	$OUTPUT->set_env('mailbox', $RCMAIL->storage->get_folder());
AM	67	$OUTPUT->set_env('uid', $uid);
	68	$OUTPUT->set_env('part', $part_id);
	69	$OUTPUT->set_env('filename', $filename);
049428	70
c97625	71	$OUTPUT->send('messagepart');
AM	72	exit;
8fa58e	73	}
4e17e6	74
031491	75	// render thumbnail of an image attachment
TB	76	else if ($_GET['_thumb']) {
c97625	77	$pid = rcube_utils::get_input_value('_part', rcube_utils::INPUT_GET);
AM	78	if ($part = $MESSAGE->mime_parts[$pid]) {
	79	$thumbnail_size = $RCMAIL->config->get('image_thumbnail_size', 240);
	80	$temp_dir = $RCMAIL->config->get('temp_dir');
	81	$mimetype = $part->mimetype;
	82	$file_ident = $MESSAGE->headers->messageID . ':' . $part->mime_id . ':' . $part->size . ':' . $part->mimetype;
	83	$cache_basename = $temp_dir . '/' . md5($file_ident . ':' . $RCMAIL->user->ID . ':' . $thumbnail_size);
84af0d	84	$cache_file = $cache_basename . '.thumb';
031491	85
c97625	86	// render thumbnail image if not done yet
AM	87	if (!is_file($cache_file)) {
84af0d	88	if ($fp = fopen(($orig_name = $cache_basename . '.tmp'), 'w')) {
26c993	89	$MESSAGE->get_part_body($part->mime_id, false, 0, $fp);
c97625	90	fclose($fp);
031491	91
c97625	92	$image = new rcube_image($orig_name);
AM	93	if ($imgtype = $image->resize($thumbnail_size, $cache_file, true)) {
	94	$mimetype = 'image/' . $imgtype;
	95	unlink($orig_name);
	96	}
7bbefd	97	else if (stripos($mimetype, 'image/svg') === 0) {
AM	98	$content = rcmail_svg_filter(file_get_contents($orig_name));
	99	file_put_contents($cache_file, $content);
	100	unlink($orig_name);
	101	}
c97625	102	else {
AM	103	rename($orig_name, $cache_file);
	104	}
	105	}
19cc5b	106	}
AM	107
c97625	108	if (is_file($cache_file)) {
AM	109	header('Content-Type: ' . $mimetype);
	110	readfile($cache_file);
19cc5b	111	}
8fa58e	112	}
8d4bcd	113
4e17e6	114	exit;
8fa58e	115	}
4e17e6	116
c97625	117	else if (strlen($part_id)) {
AM	118	if ($part = $MESSAGE->mime_parts[$part_id]) {
	119	$mimetype = rcmail_fix_mimetype($part->mimetype);
	120
	121	// allow post-processing of the message body
	122	$plugin = $RCMAIL->plugins->exec_hook('message_part_get', array(
	123	'uid' => $MESSAGE->uid,
	124	'id' => $part->mime_id,
	125	'mimetype' => $mimetype,
	126	'part' => $part,
	127	'download' => !empty($_GET['_download'])
	128	));
	129
	130	if ($plugin['abort']) {
	131	exit;
	132	}
	133
	134	// overwrite modified vars from plugin
	135	$mimetype = $plugin['mimetype'];
	136	$extensions = rcube_mime::get_mime_extensions($mimetype);
	137
	138	if ($plugin['body']) {
48ba44	139	$body = $plugin['body'];
c97625	140	}
AM	141
	142	// compare file mimetype with the stated content-type headers and file extension to avoid malicious operations
	143	if (!empty($_REQUEST['_embed']) && empty($_REQUEST['_nocheck'])) {
	144	$file_extension = strtolower(pathinfo($part->filename, PATHINFO_EXTENSION));
	145
	146	// 1. compare filename suffix with expected suffix derived from mimetype
afd5e4	147	$valid = $file_extension && in_array($file_extension, (array)$extensions) \|\| empty($extensions) \|\| !empty($_REQUEST['_mimeclass']);
c97625	148
AM	149	// 2. detect the real mimetype of the attachment part and compare it with the stated mimetype and filename extension
	150	if ($valid \|\| !$file_extension \|\| $mimetype == 'application/octet-stream' \|\| stripos($mimetype, 'text/') === 0) {
48ba44	151	$tmp_body = $body ?: $MESSAGE->get_part_body($part->mime_id, false, 2048);
c97625	152
AM	153	// detect message part mimetype
48ba44	154	$real_mimetype = rcube_mime::file_content_type($tmp_body, $part->filename, $mimetype, true, true);
c97625	155	list($real_ctype_primary, $real_ctype_secondary) = explode('/', $real_mimetype);
AM	156
	157	// accept text/plain with any extension
	158	if ($real_mimetype == 'text/plain' && $real_mimetype == $mimetype) {
	159	$valid_extension = true;
	160	}
556d28	161	// ignore differences in text/* mimetypes. Filetype detection isn't very reliable here
AM	162	else if ($real_ctype_primary == 'text' && strpos($mimetype, $real_ctype_primary) === 0) {
	163	$real_mimetype = $mimetype;
	164	$valid_extension = true;
	165	}
	166	// ignore filename extension if mimeclass matches (#1489029)
	167	else if (!empty($_REQUEST['_mimeclass']) && $real_ctype_primary == $_REQUEST['_mimeclass']) {
	168	$valid_extension = true;
	169	}
	170	else {
	171	// get valid file extensions
	172	$extensions = rcube_mime::get_mime_extensions($real_mimetype);
c8468c	173	$valid_extension = !$file_extension \|\| empty($extensions) \|\| in_array($file_extension, (array)$extensions);
556d28	174	}
c97625	175
AM	176	// fix mimetype for images wrongly declared as octet-stream
	177	if ($mimetype == 'application/octet-stream' && strpos($real_mimetype, 'image/') === 0 && $valid_extension) {
	178	$mimetype = $real_mimetype;
	179	}
	180
afd5e4	181	// "fix" real mimetype the same way the original is before comparison
AM	182	$real_mimetype = rcmail_fix_mimetype($real_mimetype);
	183
	184	$valid = $real_mimetype == $mimetype && $valid_extension;
c97625	185	}
AM	186	else {
	187	$real_mimetype = $mimetype;
	188	}
	189
	190	// show warning if validity checks failed
	191	if (!$valid) {
	192	// send blocked.gif for expected images
	193	if (empty($_REQUEST['_mimewarning']) && strpos($mimetype, 'image/') === 0) {
	194	// Do not cache. Failure might be the result of a misconfiguration, thus real content should be returned once fixed.
c6efcf	195	$content = $RCMAIL->get_resource_content('blocked.gif');
c97625	196	$OUTPUT->nocacheing_headers();
AM	197	header("Content-Type: image/gif");
	198	header("Content-Transfer-Encoding: binary");
c6efcf	199	header("Content-Length: " . strlen($content));
AM	200	echo $content;
c97625	201	}
AM	202	else { // html warning with a button to load the file anyway
	203	$OUTPUT = new rcmail_html_page();
	204	$OUTPUT->write(html::tag('html', null, html::tag('body', 'embed',
	205	html::div(array('class' => 'rcmail-inline-message rcmail-inline-warning'),
	206	$RCMAIL->gettext(array(
	207	'name' => 'attachmentvalidationerror',
	208	'vars' => array(
	209	'expected' => $mimetype . ($file_extension ? " (.$file_extension)" : ''),
	210	'detected' => $real_mimetype . ($extensions[0] ? " (.$extensions[0])" : ''),
	211	)
	212	))
	213	. html::p(array('class' => 'rcmail-inline-buttons'),
	214	html::tag('button', array(
	215	'onclick' => "location.href='" . $RCMAIL->url(array_merge($_GET, array('_nocheck' => 1))) . "'"
	216	),
	217	$RCMAIL->gettext('showanyway'))
	218	)
	219	))));
	220	}
	221
	222	exit;
	223	}
	224	}
	225
	226
	227	// TIFF to JPEG conversion, if needed
	228	$tiff_support = !empty($_SESSION['browser_caps']) && !empty($_SESSION['browser_caps']['tif']);
	229	if (!empty($_REQUEST['_embed']) && !$tiff_support
8968f9	230	&& rcube_image::is_convertable('image/tiff')
c97625	231	&& rcmail_part_image_type($part) == 'image/tiff'
AM	232	) {
	233	$tiff2jpeg = true;
	234	$mimetype = 'image/jpeg';
	235	}
	236
	237
	238	$browser = $RCMAIL->output->browser;
	239	list($ctype_primary, $ctype_secondary) = explode('/', $mimetype);
	240
	241	if (!$plugin['download'] && $ctype_primary == 'text') {
	242	header("Content-Type: text/$ctype_secondary; charset=" . ($part->charset ? $part->charset : RCUBE_CHARSET));
	243	}
	244	else {
	245	header("Content-Type: $mimetype");
	246	header("Content-Transfer-Encoding: binary");
	247	}
	248
	249	// deliver part content
	250	if ($ctype_primary == 'text' && $ctype_secondary == 'html' && empty($plugin['download'])) {
	251	// Check if we have enough memory to handle the message in it
	252	// #1487424: we need up to 10x more memory than the body
	253	if (!rcube_utils::mem_check($part->size * 10)) {
	254	$out = '<body>' . $RCMAIL->gettext('messagetoobig'). ' '
	255	. html::a('?_task=mail&_action=get&_download=1&_uid='.$MESSAGE->uid.'&_part='.$part->mime_id
c83940	256	.'&_mbox='. urlencode($MESSAGE->folder), $RCMAIL->gettext('download')) . '</body></html>';
c97625	257	}
AM	258	else {
	259	// get part body if not available
48ba44	260	if (!isset($body)) {
AM	261	$body = $MESSAGE->get_part_body($part->mime_id, true);
c97625	262	}
AM	263
	264	// show images?
	265	rcmail_check_safe($MESSAGE);
	266
	267	// render HTML body
48ba44	268	$out = rcmail_print_body($body, $part, array('safe' => $MESSAGE->is_safe, 'inline_html' => false));
c97625	269
AM	270	// insert remote objects warning into HTML body
	271	if ($REMOTE_OBJECTS) {
	272	$body_start = 0;
	273	if ($body_pos = strpos($out, '<body')) {
	274	$body_start = strpos($out, '>', $body_pos) + 1;
	275	}
	276
	277	$out = substr($out, 0, $body_start)
	278	. html::div(array('class' => 'rcmail-inline-message rcmail-inline-warning'),
	279	rcube::Q($RCMAIL->gettext('blockedimages')) . ' ' .
	280	html::tag('button',
	281	array('onclick' => "location.href='" . $RCMAIL->url(array_merge($_GET, array('_safe' => 1))) . "'"),
	282	rcube::Q($RCMAIL->gettext('showimages')))
	283	)
	284	. substr($out, $body_start);
	285	}
	286	}
	287
	288	// check connection status
48ba44	289	if ($part->size && empty($body)) {
c97625	290	check_storage_status();
AM	291	}
	292
	293	$OUTPUT = new rcmail_html_page();
	294	$OUTPUT->write($out);
	295	}
	296	else {
	297	// don't kill the connection if download takes more than 30 sec.
	298	@set_time_limit(0);
	299
	300	$filename = rcmail_attachment_name($part);
	301
5515db	302	if ($browser->ie)
c97625	303	$filename = rawurlencode($filename);
AM	304	else
	305	$filename = addcslashes($filename, '"');
	306
	307	$disposition = !empty($plugin['download']) ? 'attachment' : 'inline';
	308
	309	// Workaround for nasty IE bug (#1488844)
	310	// If Content-Disposition header contains string "attachment" e.g. in filename
	311	// IE handles data as attachment not inline
	312	if ($disposition == 'inline' && $browser->ie && $browser->ver < 9) {
	313	$filename = str_ireplace('attachment', 'attach', $filename);
	314	}
	315
	316	// add filename extension if missing
	317	if (!pathinfo($filename, PATHINFO_EXTENSION) && ($extensions = rcube_mime::get_mime_extensions($mimetype))) {
	318	$filename .= '.' . $extensions[0];
	319	}
	320
	321	header("Content-Disposition: $disposition; filename=\"$filename\"");
	322
	323	// handle tiff to jpeg conversion
	324	if (!empty($tiff2jpeg)) {
	325	$temp_dir = unslashify($RCMAIL->config->get('temp_dir'));
	326	$file_path = tempnam($temp_dir, 'rcmAttmnt');
	327
	328	// write content to temp file
48ba44	329	if ($body) {
AM	330	$saved = file_put_contents($file_path, $body);
c97625	331	}
AM	332	else if ($part->size) {
	333	$fd = fopen($file_path, 'w');
48ba44	334	$saved = $MESSAGE->get_part_body($part->mime_id, false, 0, $fd);
c97625	335	fclose($fd);
AM	336	}
	337
	338	// convert image to jpeg and send it to the browser
7bbefd	339	if ($sent = $saved) {
c97625	340	$image = new rcube_image($file_path);
AM	341	if ($image->convert(rcube_image::TYPE_JPG, $file_path)) {
	342	header("Content-Length: " . filesize($file_path));
	343	readfile($file_path);
	344	}
	345	unlink($file_path);
	346	}
	347	}
	348	else {
7bbefd	349	$sent = rcmail_message_part_output($body, $part, $mimetype, $plugin['download']);
c97625	350	}
AM	351
	352	// check connection status
	353	if ($part->size && !$sent) {
	354	check_storage_status();
	355	}
	356	}
	357
	358	exit;
	359	}
	360	}
4e17e6	361	// print message
8fa58e	362	else {
c97625	363	// send correct headers for content type
AM	364	header("Content-Type: text/html");
4e17e6	365
c97625	366	$cont = "<html>\n<head><title></title>\n</head>\n<body>";
AM	367	$cont .= rcmail_message_body(array());
	368	$cont .= "\n</body>\n</html>";
4e17e6	369
c97625	370	$OUTPUT = new rcmail_html_page();
AM	371	$OUTPUT->write($cont);
4e17e6	372
c97625	373	exit;
8fa58e	374	}
4e17e6	375
T	376
	377	// if we arrive here, the requested part was not found
	378	header('HTTP/1.1 404 Not Found');
	379	exit;
	380
eaf383	381	/**
AM	382	* Handles nicely storage connection errors
	383	*/
4bfe4e	384	function check_storage_status()
AM	385	{
	386	$error = rcmail::get_instance()->storage->get_error_code();
	387
	388	// Check if we have a connection error
	389	if ($error == rcube_imap_generic::ERROR_BAD) {
	390	ob_end_clean();
	391
	392	// Get action is often executed simultanously.
	393	// Some servers have MAXPERIP or other limits.
	394	// To workaround this we'll wait for some time
	395	// and try again (once).
	396	// Note: Random sleep interval is used to minimize concurency
	397	// in getting message parts
	398
	399	if (!isset($_GET['_redirected'])) {
	400	usleep(rand(10,30)*100000); // 1-3 sec.
	401	header('Location: ' . $_SERVER['REQUEST_URI'] . '&_redirected=1');
	402	}
	403	else {
6b2b2e	404	rcube::raise_error(array(
4bfe4e	405	'code' => 500, 'type' => 'php',
AM	406	'file' => __FILE__, 'line' => __LINE__,
	407	'message' => 'Unable to get/display message part. IMAP connection error'),
	408	true, true);
	409	}
	410
	411	// Don't kill session, just quit (#1486995)
	412	exit;
	413	}
	414	}
049428	415
eaf383	416	/**
AM	417	* Attachment properties table
	418	*/
049428	419	function rcmail_message_part_controls($attrib)
AM	420	{
	421	global $MESSAGE, $RCMAIL;
	422
6b2b2e	423	$part = asciiwords(rcube_utils::get_input_value('_part', rcube_utils::INPUT_GPC));
049428	424	if (!is_object($MESSAGE) \|\| !is_array($MESSAGE->parts)
AM	425	\|\| !($_GET['_uid'] && $_GET['_part']) \|\| !$MESSAGE->mime_parts[$part]
	426	) {
	427	return '';
	428	}
	429
	430	$part = $MESSAGE->mime_parts[$part];
	431	$table = new html_table(array('cols' => 2));
	432
6b2b2e	433	$table->add('title', rcube::Q($RCMAIL->gettext('namex')).':');
AM	434	$table->add('header', rcube::Q(rcmail_attachment_name($part)));
049428	435
6b2b2e	436	$table->add('title', rcube::Q($RCMAIL->gettext('type')).':');
AM	437	$table->add('header', rcube::Q($part->mimetype));
049428	438
6b2b2e	439	$table->add('title', rcube::Q($RCMAIL->gettext('size')).':');
AM	440	$table->add('header', rcube::Q($RCMAIL->message_part_size($part)));
049428	441
AM	442	return $table->show($attrib);
	443	}
	444
eaf383	445	/**
AM	446	* Attachment preview frame
	447	*/
049428	448	function rcmail_message_part_frame($attrib)
AM	449	{
	450	global $MESSAGE, $RCMAIL;
	451
6b2b2e	452	$part = $MESSAGE->mime_parts[asciiwords(rcube_utils::get_input_value('_part', rcube_utils::INPUT_GPC))];
049428	453	$ctype_primary = strtolower($part->ctype_primary);
AM	454
	455	$attrib['src'] = './?' . str_replace('_frame=', ($ctype_primary=='text' ? '_embed=' : '_preload='), $_SERVER['QUERY_STRING']);
	456
	457	$RCMAIL->output->add_gui_object('messagepartframe', $attrib['id']);
	458
	459	return html::iframe($attrib);
	460	}
7bbefd	461
AM	462	/**
	463	* Output attachment body with content filtering
	464	*/
	465	function rcmail_message_part_output($body, $part, $mimetype, $download)
	466	{
	467	global $MESSAGE, $RCMAIL;
	468
	469	if (!$part->size && !$body) {
	470	return false;
	471	}
	472
	473	$browser = $RCMAIL->output->browser;
	474	$secure = stripos($mimetype, 'image/') === false \|\| $download;
	475
	476	// Remove <script> in SVG images
	477	if (!$secure && stripos($mimetype, 'image/svg') === 0) {
	478	if (!$body) {
	479	$body = $MESSAGE->get_part_body($part->mime_id, false);
	480	if (empty($body)) {
	481	return false;
	482	}
	483	}
	484
	485	echo rcmail_svg_filter($body);
	486	return true;
	487	}
	488
	489	// Remove dangerous content in images for older IE (to be removed)
	490	if (!$secure && $browser->ie && $browser->ver <= 8) {
	491	if ($body) {
	492	echo preg_match('/<(script\|iframe\|object)/i', $body) ? '' : $body;
	493	return true;
	494	}
	495	else {
	496	$stdout = fopen('php://output', 'w');
	497	stream_filter_register('rcube_content', 'rcube_content_filter') or die('Failed to register content filter');
	498	stream_filter_append($stdout, 'rcube_content');
	499	return $MESSAGE->get_part_body($part->mime_id, true, 0, $stdout);
	500	}
	501	}
	502
	503	if ($body && !$download) {
	504	header("Content-Length: " . strlen($body));
	505	echo $body;
	506	return true;
	507	}
	508
	509	// Don't be tempted to set Content-Length to $part->d_parameters['size'] (#1490482)
	510	// RFC2183 says "The size parameter indicates an approximate size"
	511
	512	return $MESSAGE->get_part_body($part->mime_id, false, 0, -1);
	513	}
	514
	515	/**
	516	* Remove <script> in SVG images
	517	*/
	518	function rcmail_svg_filter($body)
	519	{
	520	$dom = new DOMDocument;
	521	$dom->loadXML($body);
	522
	523	foreach ($dom->getElementsByTagName('script') as $node) {
	524	$node->parentNode->removeChild($node);
	525	}
	526
	527	return $dom->saveXML() ?: '';
	528	}