Home / exploits Fortinet FortiAuthenticator XSS / Disclosure / Bypass
Posted on 29 January 2015
( , ) (, . '.' ) ('. ', ). , ('. ( ) ( (_,) .'), ) _ _, / _____/ / _ ____ ____ _____ \____ ==/ /_ _/ ___/ _ / / / | \ \__( <_> ) Y Y /______ /\___|__ / \___ >____/|__|_| / / /.-. / /:wq (x.0) '=.|w|.=' _=''"''=. presents.. Fortinet FortiAuthenticator Multiple Vulnerabilities Affected Versions: Verified on FortiAuthenticator v300 build 0007 PDF: http://www.security-assessment.com/files/documents/advisory/Fortinet_FortiAuthenticator_Multiple_Vulnerabilities.pdf +-------------+ | Description | +-------------+ This advisory details multiple vulnerabilities found within the Fortinet FortiAuthenticator virtual appliance. The FortiAuthenticator is a user identity management appliance, supporting two factor authentication, RADIUS, LDAP, 802.1x Wireless Authentication, Certificate management and single sign on. The FortiAuthenticator appliance was found to contain a subshell bypass vulnerability, allowing remote administrators to gain root level access via the command line. Local file and password disclosure vulnerabilities were discovered, as well as a Reflected Cross Site Scripting vulnerability within the SCEP system. +--------------+ | Exploitation | +--------------+ --[ dbgcore_enable_shell_access Subshell Bypass By logging into the Fortinet Authenticator and executing the ‘shell’ command, a malicious user can gain a root /bin/bash shell on the server. However, unless the /tmp/privexec/dbgcore_enable_shell_access file exists (the contents of this file are irrelevant), then the command returns ‘shell: No such command.' If the file is present, then the command succeeds and a root shell is given. The ‘/tmp/privexec/dbgcore_enable_shell_access’ file can be created by using the ‘load-debug-kit’ command and specifying a network accessible tftp server with the relevant debug kit. The debug kits were found to be generated by an internal Fortinet tool called ‘mkprivexec’. The ‘load-debug-kit’ command expects encrypted binaries which are subsequently executed. An attacker that can either generate a valid debug kit or create the appropriate file in /tmp/privexec can therefore get a root shell. This is likely a workaround for CVE-2013-6990, however an attacker can still obtain root level command line access with some additional steps. --[ Local File Disclosure A malicious user can pass the ‘-f’ flag to the ‘dig’ command and read files from the filesystem. An example would be executing 'dig -f /etc/passwd' and observing the dig commands output, retrieving the /etc/passwd files contents. --[ Password Disclosure A malicious user may use the debug logging functionality within the Fortinet FortiAuthenticator administrative console to obtain the passwords of the PostgreSQL database users. The disclosed passwords were found to be weak and are static across Fortinet FortiAuthenticator appliances. The following credentials were enumerated: +-----------------+ |Username:Password| +-----------------+ | slony : slony | |www-data:www-data| +-----------------+ --[ Reflected Cross Site Scripting By coercing a legitimate user (usually through a social engineering attack) to visit a specific FortiAuthenticator URL, an attacker may execute malicious JavaScript in the context of the user’s browser. This can subsequently be used to harm the user’s browser or hijack their session. This is due to the ‘operation’ parameter in the SCEP service being reflected to the end user without sufficient input validation and output scrubbing. The following URL can be used to replicate the Reflected Cross Site Scripting vulnerability: https://<FortiAuthenticatorIP>/cert/scep/?operation=<script>alert(1)</script> +----------+ | Solution | +----------+ No official solution is currently available for these vulnerabilities. Email correspondence with Fortinet suggests that the Local File Disclosure and Password Disclosure vulnerabilities have been resolved in version 3.2. No official documentation was found to confirm this. +---------------------+ | Disclosure Timeline | +---------------------+ 08/10/2014 - Initial email sent to Fortinet PSIRT team. 09/10/2014 - Advisory documents sent to Fortinet. 15/10/2014 - Acknowledgement of advisories from Fortinet. 16/10/2014 - Fortinet advised the Local File and Password disclosure issues would be resolved in the 3.2 release. 31/10/2014 - Additional information sent to Fortinet RE Reflected XSS 03/11/2014 - Additional information sent to Fortinet RE Reflected XSS 02/12/2014 - Update requested from Fortinet. 13/12/2014 - Update requested from Fortinet. 29/01/2015 - Advisory Release. +-------------------------------+ | About Security-Assessment.com | +-------------------------------+ Security-Assessment.com is Australasia's leading team of Information Security consultants specialising in providing high quality Information Security services to clients throughout the Asia Pacific region. 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