CVE-2007-6704 in FirePass 4100
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in F5 FirePass 4100 SSL VPN 5.4.1 through 5.5.2 and 6.0 through 6.0.1, when pre-logon sequences are enabled, allow remote attackers to inject arbitrary web script or HTML via the query string to (1) my.activation.php3 and (2) my.logon.php3.
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Analysis
by VulDB Data Team • 12/01/2024
The vulnerability identified as CVE-2007-6704 represents a critical cross-site scripting flaw affecting F5 FirePass 4100 SSL VPN appliances running specific versions from 5.4.1 through 5.5.2 and 6.0 through 6.0.1. This vulnerability specifically manifests during pre-logon sequences when the appliance fails to properly sanitize user input parameters, creating an avenue for remote attackers to execute malicious scripts within the context of authenticated sessions. The affected components my.activation.php3 and my.logon.php3 serve as primary attack vectors where query string parameters are directly processed without adequate validation or sanitization mechanisms.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious URLs containing script code within the query string parameters that are then passed to the vulnerable php3 scripts. These scripts fail to implement proper input validation or output encoding, allowing attackers to inject arbitrary HTML or JavaScript code that executes in the victim's browser context. The vulnerability is particularly dangerous because it operates during pre-logon sequences, meaning that malicious code can be executed before users establish legitimate authentication sessions, potentially compromising user credentials or session tokens. The flaw directly maps to CWE-79 which defines Cross-Site Scripting as a weakness where untrusted data is sent to a web browser without proper validation or encoding.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, credential theft, and data exfiltration from authenticated users. When users navigate to maliciously crafted URLs, the injected scripts can capture session cookies, redirect users to phishing sites, or manipulate the user interface to display fraudulent content. The pre-logon nature of the vulnerability means that attackers can compromise users even before they establish legitimate connections to the VPN infrastructure, creating a significant risk for organizations relying on these appliances for secure remote access. This vulnerability aligns with ATT&CK technique T1566 which describes social engineering tactics used to gain initial access to systems, and T1071.004 which covers application layer protocol tunneling.
Organizations should implement immediate mitigations including disabling pre-logon sequences if not required for business operations, implementing proper input validation and output encoding mechanisms, and deploying web application firewalls to detect and block malicious query parameters. The most effective long-term solution involves upgrading to patched versions of the F5 FirePass software where input sanitization has been properly implemented. Security teams should also conduct comprehensive network monitoring to detect any suspicious traffic patterns that might indicate exploitation attempts. Additionally, user education regarding the dangers of clicking untrusted links and the importance of verifying URLs before accessing VPN portals should be emphasized as part of a layered defense strategy. The vulnerability demonstrates the critical importance of proper input validation in web applications and highlights the need for comprehensive security testing during the development lifecycle to prevent similar issues in other network infrastructure components.