CVE-2017-16182 in serverxxx
Summary
by MITRE
serverxxx is a static file server. serverxxx is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/16/2020
The vulnerability identified as CVE-2017-16182 affects serverxxx, a static file server implementation that suffers from a critical directory traversal flaw. This vulnerability stems from inadequate input validation and path handling within the server's file access mechanisms, allowing remote attackers to manipulate file paths through specially crafted URL requests. The flaw enables unauthorized access to the underlying filesystem by exploiting the server's failure to properly sanitize user-supplied path components, specifically the "../" sequence that represents parent directory traversal. This represents a fundamental security weakness in the application's file system access controls and input validation processes.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious URLs containing directory traversal sequences such as "../" or similar path manipulation patterns. The server processes these requests without proper validation, allowing the traversal to move up the directory hierarchy and access files outside the intended document root. This flaw directly maps to CWE-22, which defines path traversal vulnerabilities as weaknesses that occur when applications allow user-controllable input to influence file system access. The vulnerability exists at the application level where user input is not properly normalized or validated before being used in file system operations, creating a direct pathway for attackers to access sensitive files, configuration data, or system resources that should remain protected.
The operational impact of this vulnerability is severe and multifaceted, potentially exposing sensitive data, system configuration files, and application resources to unauthorized access. Attackers can leverage this vulnerability to read arbitrary files on the server, including but not limited to application source code, database configuration files, authentication credentials, and system logs. This access could lead to privilege escalation, data exfiltration, and further exploitation of the compromised system. The vulnerability also aligns with ATT&CK technique T1083, which describes the discovery of system information through directory listing and file access, providing attackers with valuable intelligence for subsequent phases of their attack campaigns. Organizations running affected serverxxx implementations face significant risk of data breaches and system compromise, particularly in environments where the server hosts sensitive or confidential information.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization mechanisms. The primary defense involves ensuring that all user-supplied path components are properly validated and normalized before being used in file system operations. This includes implementing strict path validation that rejects or removes directory traversal sequences, enforcing proper access controls through secure coding practices, and implementing proper sandboxing or chroot mechanisms to limit file system access. Organizations should also consider implementing web application firewalls that can detect and block malicious path traversal attempts, while regularly updating and patching the server software to address known vulnerabilities. The remediation process should include comprehensive code review to identify and eliminate similar patterns throughout the application, ensuring that all file access operations properly validate input and maintain appropriate security boundaries. Additionally, implementing principle of least privilege access controls and regular security assessments can help prevent exploitation of similar vulnerabilities in the future.