CVE-2012-4739 in SSL VPN
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Barracuda SSL VPN before 2.2.2.203 (2012-07-05) allow remote attackers to inject arbitrary web script or HTML via the (1) policyLaunching, (2) resourcePrefix, or (3) actionPath parameter in showUserResourceCategories.do; (4) list or (5) path parameter to fileSystem.do; or (6) return-To parameter to launchAgent.do.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/01/2024
The vulnerability identified as CVE-2012-4739 represents a critical cross-site scripting weakness in Barracuda SSL VPN appliances prior to version 2.2.2.203 released on July 5, 2012. This vulnerability resides within the web-based management interface of the SSL VPN appliance and affects multiple endpoints within the application's request processing pipeline. The flaw stems from insufficient input validation and output encoding mechanisms that fail to properly sanitize user-supplied parameters before incorporating them into dynamically generated web content. Security researchers have identified six distinct vulnerable parameters across three different servlet endpoints, demonstrating a systemic weakness in the application's data handling architecture that allows attackers to inject malicious scripts into the victim's browser context.
The technical exploitation of this vulnerability occurs through the manipulation of specific HTTP parameters that are processed by the affected servlets. The policyLaunching, resourcePrefix, and actionPath parameters within the showUserResourceCategories.do endpoint represent the first vector for injection attacks, while the list and path parameters in fileSystem.do constitute the second attack surface. The return-To parameter in launchAgent.do provides the third vector, all of which are susceptible to script injection when improperly validated. These parameters are typically used for legitimate navigation and resource management functions within the SSL VPN interface, making the attack vectors particularly insidious as they leverage normal application behavior to deliver malicious payloads. The vulnerability is classified under CWE-79 as Cross-Site Scripting, which specifically addresses the injection of executable code into web pages viewed by other users.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking, as it provides attackers with the capability to execute arbitrary commands within the context of a victim's browser session. An attacker could potentially redirect users to malicious websites, steal session cookies, perform unauthorized actions on behalf of users, or even escalate privileges within the VPN environment. The remote nature of the attack means that exploitation can occur from any location without requiring physical access to the network or appliance, making it particularly dangerous for organizations that rely on SSL VPN for remote access. This vulnerability particularly affects enterprises using Barracuda SSL VPN appliances for secure remote access, potentially compromising sensitive corporate data and network resources that are typically protected by the VPN infrastructure.
Organizations should immediately implement comprehensive mitigation strategies including patching to the latest available version of Barracuda SSL VPN software, which addresses the input validation deficiencies in the affected endpoints. Network administrators should also consider implementing additional security controls such as web application firewalls that can detect and block malicious script injection attempts, and regular security assessments of the SSL VPN environment to identify other potential vulnerabilities. The vulnerability demonstrates the importance of proper input sanitization and output encoding practices, which align with ATT&CK technique T1566.001 for Initial Access through Valid Accounts and T1059.001 for Command and Scripting Interpreter. Additionally, organizations should establish monitoring procedures to detect anomalous parameter usage patterns that might indicate exploitation attempts, as well as conduct security awareness training for administrators to recognize potential attack vectors. The remediation process should also include reviewing and hardening the web application's configuration to ensure that all user-supplied inputs are properly validated and that appropriate output encoding is applied to prevent script execution in browser contexts.