CVE-2017-16145 in sspa
Summary
by MITRE
sspa is a server dedicated to single-page apps. sspa is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
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Analysis
by VulDB Data Team • 02/16/2020
The sspa server represents a specialized web infrastructure designed to serve single-page applications with optimized performance and minimal server-side processing. This type of server architecture typically handles static content delivery and API routing for modern web applications. The vulnerability identified in CVE-2017-16145 manifests as a critical directory traversal flaw that fundamentally compromises the server's security boundaries. Attackers can exploit this weakness by manipulating URL parameters to include directory traversal sequences such as "../" which allows them to navigate beyond the intended document root and access arbitrary files on the underlying filesystem. This vulnerability directly maps to CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The attack vector operates through the server's URL parsing mechanism, where input validation fails to properly sanitize user-supplied paths, enabling malicious actors to bypass normal access controls and potentially gain access to sensitive system files, configuration data, or other restricted resources. The operational impact of this vulnerability extends beyond simple information disclosure, as it can lead to complete system compromise when combined with other exploitation techniques. An attacker who successfully exploits this directory traversal vulnerability can potentially access system configuration files, application source code, database credentials, and other sensitive data that should remain isolated from external access. This weakness also enables further attack progression including privilege escalation, lateral movement within the network, and potential persistence mechanisms. The vulnerability demonstrates a critical failure in input validation and access control implementation within the server's file handling routines. From an ATT&CK framework perspective, this vulnerability aligns with T1083 (File and Directory Discovery) and T1566 (Phishing with Malicious Attachment) as attackers can use the discovered files to craft more sophisticated attacks. The attack surface is particularly concerning for applications that rely on sspa servers for serving sensitive content, as the vulnerability can be exploited through simple URL manipulation without requiring advanced technical skills. Organizations using this server software face significant risk of data breaches, regulatory compliance violations, and potential system compromise. The vulnerability's exploitation requires minimal effort and can be automated, making it particularly dangerous in environments where such servers are exposed to untrusted networks or public internet access. Mitigation strategies should include implementing proper input validation and sanitization of all user-supplied URLs, enforcing strict directory traversal restrictions, and deploying web application firewalls that can detect and block suspicious path traversal attempts. Additionally, regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other components of the application stack. The server should be configured to operate within a restricted environment with minimal privileges and proper network segmentation to limit the potential impact of successful exploitation attempts.