CVE-2016-6154 in Fireware
Summary
by MITRE
The authentication applet in Watchguard Fireware 11.11 Operating System has reflected XSS (this can also cause an open redirect).
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Analysis
by VulDB Data Team • 12/01/2023
The vulnerability identified as CVE-2016-6154 resides within the authentication applet of Watchguard Fireware 11.11 Operating System, representing a critical security flaw that enables reflected cross-site scripting attacks. This issue specifically affects the web-based authentication interface that users encounter when attempting to access the firewall management console. The vulnerability stems from inadequate input validation and output encoding mechanisms within the authentication applet's handling of user-supplied parameters. When a user submits authentication credentials through the web interface, the application fails to properly sanitize input data before incorporating it into the HTTP response, creating an avenue for malicious actors to inject malicious scripts that execute in the context of the victim's browser session.
The technical implementation of this reflected XSS vulnerability occurs when the authentication applet processes URL parameters or form fields without adequate sanitization measures. Attackers can craft malicious URLs containing script payloads that are then reflected back to the user's browser when the authentication page is rendered. These reflected scripts can execute in the victim's browser context with the privileges of the authenticated user, potentially enabling session hijacking, credential theft, or unauthorized administrative actions. The vulnerability also encompasses open redirect capabilities, allowing attackers to construct URLs that redirect users to malicious third-party domains while maintaining the appearance of legitimate authentication pages, thereby facilitating phishing attacks and credential harvesting.
The operational impact of CVE-2016-6154 extends beyond simple script execution, as it provides attackers with a potential pathway to escalate privileges and compromise the entire firewall infrastructure. Since the authentication applet serves as the primary gateway for administrative access to the Watchguard Fireware system, successful exploitation could enable attackers to gain full administrative control over the firewall configuration, including the ability to modify security policies, view sensitive network traffic, and potentially establish persistent backdoors. This vulnerability directly violates the principle of least privilege and undermines the integrity of the authentication process that should protect critical network infrastructure from unauthorized access.
Organizations utilizing Watchguard Fireware 11.11 systems face significant risk exposure from this vulnerability, particularly in environments where the firewall serves as a critical security boundary. The reflected XSS nature means that exploitation can occur through simple web-based attacks, making it accessible to attackers with minimal technical expertise. Security practitioners should consider this vulnerability in the context of the MITRE ATT&CK framework, specifically under the T1190 technique for Exploit Public-Facing Application, and T1566 for Phishing with Social Engineering. The vulnerability aligns with CWE-79 which describes Cross-Site Scripting flaws, and represents a clear violation of secure coding practices that mandate proper input validation and output encoding. Organizations should implement immediate mitigations including applying vendor patches, implementing web application firewalls, and conducting thorough security assessments of their authentication infrastructure to prevent exploitation attempts.
The broader implications of this vulnerability highlight the critical importance of secure authentication mechanisms in network security appliances. Firewall systems serve as the first line of defense in many enterprise environments, making them prime targets for attackers seeking to establish persistent access to critical network resources. The combination of reflected XSS and open redirect capabilities creates a particularly dangerous attack vector that can be leveraged for both reconnaissance and active exploitation phases of cyber attacks. Security teams must recognize that vulnerabilities in authentication systems can serve as stepping stones to more comprehensive compromises, emphasizing the need for robust input validation and output encoding practices throughout all application components. This vulnerability serves as a reminder of the essential security requirements for maintaining the integrity and confidentiality of network infrastructure components that control access to critical enterprise resources.