CVE-2017-14615 in Watchguard
Summary
by MITRE
An FBX-5313 issue was discovered in WatchGuard Fireware before 12.0. When a failed login attempt is made to the login endpoint of the XML-RPC interface, if JavaScript code, properly encoded to be consumed by XML parsers, is embedded as value of the user element, the code will be rendered in the context of any logged in user in the Web UI visiting "Traffic Monitor" sections "Events" and "All." As a side effect, no further events will be visible in the Traffic Monitor until the device is restarted.
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Analysis
by VulDB Data Team • 11/18/2019
The vulnerability identified as CVE-2017-14615 represents a critical cross-site scripting flaw in WatchGuard Fireware versions prior to 12.0, specifically affecting the FBX-5313 component. This issue manifests through the XML-RPC interface's login endpoint where improper input validation allows malicious JavaScript code execution. The vulnerability stems from the application's failure to properly sanitize user input when processing the username element in XML requests, creating a persistent XSS vector that can be exploited by unauthorized users to inject malicious scripts into the web interface.
The technical exploitation occurs when an attacker submits a malformed XML-RPC request containing JavaScript code within the user element field. During failed login attempts, this malicious code gets rendered in the web interface context of any authenticated user who navigates to the Traffic Monitor sections, specifically the Events and All views. This behavior demonstrates a classic stored XSS vulnerability where the malicious payload is not only executed but also persists within the application's interface, making it particularly dangerous as it affects all subsequent users who access the vulnerable sections without requiring additional authentication. The vulnerability maps to CWE-79: Cross-site Scripting and aligns with ATT&CK technique T1059.007 for Scripting with the specific implementation targeting web application interfaces.
The operational impact of this vulnerability extends beyond simple script execution, as it fundamentally compromises the integrity and usability of the security monitoring interface. When the malicious code executes, it prevents further events from appearing in the Traffic Monitor until the device undergoes a complete restart, effectively creating a denial of service condition that disrupts security monitoring capabilities. This disruption can mask legitimate security events and compromise the organization's ability to detect and respond to potential threats in real-time. The vulnerability affects the availability and integrity of the security infrastructure, as the device becomes unreliable for its primary function of monitoring network traffic and security events, potentially allowing attackers to remain undetected while the system is compromised.
Organizations should immediately implement mitigations including upgrading to WatchGuard Fireware version 12.0 or later, which contains the necessary patches to address this vulnerability. Network administrators should also consider implementing additional security controls such as web application firewalls to filter malicious XML requests and monitor for suspicious patterns in authentication attempts. The vulnerability highlights the importance of proper input validation and output encoding in web applications, particularly in security-critical interfaces where user input directly influences the application's behavior. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other network security devices and applications to prevent similar exploitation vectors from being leveraged against organizational infrastructure.