CVE-2015-5664 in QNAP
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in File Station in QNAP QTS before 4.2.0 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 01/29/2019
The CVE-2015-5664 vulnerability represents a critical cross-site scripting flaw discovered in QNAP QTS (QNAP Turbo Server) versions prior to 4.2.0, specifically affecting the File Station component. This vulnerability resides within the web interface of the QNAP NAS (Network Attached Storage) devices, making it particularly dangerous as it can be exploited by remote attackers without requiring local access or authentication. The vulnerability's presence in the File Station module means that any user interacting with the web-based file management interface could potentially become a victim of this attack vector, creating a significant security risk for organizations relying on QNAP devices for their storage infrastructure.
The technical nature of this XSS vulnerability stems from insufficient input validation and output encoding within the File Station web interface components. Attackers can exploit unspecified vectors to inject malicious scripts or HTML code that will execute in the context of other users' browsers who access the compromised File Station interface. This type of vulnerability falls under CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications. The attack typically involves crafting malicious input that gets stored or processed by the application without proper sanitization, allowing the injected code to execute when other users view the affected content. The unspecified vectors suggest that multiple input points within the File Station interface could serve as potential entry points for attackers, making the vulnerability particularly concerning from a defensive perspective.
The operational impact of CVE-2015-5664 extends far beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities through the compromised user sessions. An attacker could potentially steal session cookies, redirect users to malicious websites, modify file contents, or even execute arbitrary commands on the affected NAS devices if additional vulnerabilities exist. The attack surface is particularly broad given that File Station is a core component of QNAP QTS, meaning that successful exploitation could compromise the entire storage infrastructure. This vulnerability aligns with ATT&CK technique T1059.007, which covers scripting through web shells, and represents a classic example of how web-based vulnerabilities can escalate to full system compromise. Organizations using QNAP devices in enterprise environments face significant risks as this vulnerability could be leveraged to establish persistent access to their network storage systems.
Mitigation strategies for CVE-2015-5664 should prioritize immediate remediation through the official QNAP firmware update to version 4.2.0 or later, which addresses the XSS vulnerability through proper input validation and output encoding mechanisms. Network administrators should implement additional defensive measures including web application firewalls that can detect and block malicious script injection attempts, regular security monitoring of web interface logs for suspicious activities, and user education regarding the risks of clicking on untrusted links within the File Station interface. The vulnerability demonstrates the importance of maintaining current firmware versions and implementing proper security controls such as CSP (Content Security Policy) headers to limit the impact of potential XSS attacks. Organizations should also consider implementing network segmentation to limit the potential lateral movement if an attacker successfully exploits this vulnerability, as well as establishing regular vulnerability assessment procedures to identify similar weaknesses in other networked devices and applications.