Document Title:
===============
Barracuda Bug Bounty #30 Firewall - Multiple Persistent Web Vulnerabilities
References (Source):
====================
http://www.vulnerability-lab.com/get_content.php?id=1065
Barracuda Networks Security ID (BNSEC): BNSEC-2067
Video: http://www.vulnerability-lab.com/get_content.php?id=1208
View Video: http://www.youtube.com/watch?v=-yQVyik3Ggo
Release Date:
=============
2014-02-19
Vulnerability Laboratory ID (VL-ID):
====================================
1065
Common Vulnerability Scoring System:
====================================
3.9
Product & Service Introduction:
===============================
The Barracuda Firewall goes beyond traditional network firewalls and UTMs by providing powerful network security, granular layer 7
application controls, user awareness and secure VPN connectivity combined with cloud-based malware protection, content filtering
and reporting. It alleviates the performance bottlenecks in Unified Threat Management (UTM) appliances through intelligent integration
of on-premise and cloud-based technologies. While the powerful on-premises appliance is optimized for tasks like packet forwarding and
routing, Intrusion Prevention (IPS), DNS/DHCP services and site-to-site connectivity; CPU intensive tasks like virus scanning, content
filtering and usage reporting benefit from the scalable performance and elasticity of the cloud.
(Copy of the Vendor Homepage: https://www.barracuda.com/products/firewall )
Abstract Advisory Information:
==============================
The Vulnerability Laboratory Research Team discovered multiple persistent input validation web vulnerabilities in the Barracuda Web Firewall appliance web-application.
Vulnerability Disclosure Timeline:
==================================
2013-09-04: Researcher Notification & Coordination (Benjamin Kunz Mejri)
2013-09-05: Vendor Notification (Barracuda Networks Security Team - Bug Bounty Program)
2013-09-26: Vendor Response/Feedback (Barracuda Networks Security Team - Bug Bounty Program)
2014-02-17: Vendor Fix/Patch (Barracuda Networks Developer Team) [Coordinated Disclosure]
2014-02-19: Public Disclosure (Vulnerability Laboratory)
Discovery Status:
=================
Published
Affected Product(s):
====================
Barracuda Networks
Product: Web Firewall 6.1.0.016 - Models: X100; X200; X300; X400 & X600
Exploitation Technique:
=======================
Remote
Severity Level:
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Medium
Technical Details & Description:
================================
Multiple persistent input validation web vulnerabilities are detected in the Barracuda Networks Web Firewall X300 (v6.1.0.016) Appliance Web Application.
The validation web vulnerability allows remote attackers or local low privileged application user accounts to inject (persistent) own malicious script
codes on application-side of the vulnerable module.
The vulnerability is located in the firewall menu when processing to create a custom user object with manipulated create user expresson
group credentials. Remote attackers can inject script codes to the `Login Name` & `Group Match pattern text` input fields. After the inject
the attacker can save the input via add (POST Method) to execute the persistent code in the edit listing. After the first add (inject) in the
edit formular the remote attacker is also able to add the input via `add to the second selection` listing to execute the persistent code in
both listing values of the bottom page. Remote attackers are able to add the persistent injected context to the main custom user objects
module in the predefined user objects listing. The attack vector is persistent and the request method is POST. The security risk of the
persistent input validation web vulnerabilities are estimated as medium with a cvss (common vulnerability scoring system) count of 3.8(+)|(-)3.9.
Exploitation of the vulnerability requires a low privileged application user account and low user interaction. Successful exploitation results
in session hijacking, persistent phishing, persistent external redirects & persistent manipulation of affected or connected web module context.
Vulnerable Application(s):
[+] Firewall (WAF) Appliance Application (X300Vx v6.1.0.016)
Vulnerable Module(s):
[+] Firewall > User Objects > Custom User Objects > Create User Object > Create User Expression
Vulnerable Parameter(s):
[+] login name
[+] pattern - Group Match
Affected Module(s):
[+] Firewall > User Objects > Custom User Objects > Predefined User Objects Listing
[+] Firewall > User Objects > Custom User Objects > Create User Object > Create User Expression (Group)
Proof of Concept (PoC):
=======================
The persistent input validation web vulnerabilities can be exploited by remote attackers with low privileged application user account and low user interaction.
For security demonstration or to reproduce the vulnerability follow the provided information and steps below.
Manual steps to reproduce the vulnerability:
1. Login with the user account to the barracuda networks web firewall appliance application
2. After the login open the firewall and switch to the User Objects > Custom User Objects > Create User Object module
3. Start creating via user expression a group
4. Include a random name for the main mask, and add your script code as payload to the login name and pattern (group match) input fields
5. Click the checkbox for the group match and click the add button to save the input
6. The code executes in the add box context itself and the group match or pattern values listing (bottom) [3 times]
7. Now, the attacker is also able to add the already injected persistent context to the main menu listing by a click of the add button to save at the bottom
8. The script code execution occurs when processing to watch the firewall_user_objects module index item listing
Note: The vulnerable values are login name (name) and pattner
9. Successful reproduce of the persistent web vulnerabilities!
PoC: firewall_user_objects - index listing
<[PERSISTENT INJECTED SCRIPT CODE!]>
<[PERSISTENT INJECTED SCRIPT CODE!]>
Reference(s):
https://firewall.ptest.localhost:6299/cgi-mod/index.cgi
?auth_type=Local&et=1378340277&locale=en_US&password=b9bc2762a9868729613918058ac1fb56&user=guest&primary_tab=FIREWALL&secondary_tab=firewall_user_objects
PoC: Create User Object > Create User Expression - Listing
Group Match
Pattern
a%20>"<[PERSISTENT INJECTED SCRIPT CODE!]">
List of user group patterns according to efficient authentication method.
If the check box is cleared, only one list item may match. Default: Off
