CVE-2017-16148 in serve46
Summary
by MITRE
serve46 is a static file server. serve46 is vulnerable to a directory traversal issue, giving an attacker access to the filesystem by placing "../" in the url.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/16/2020
The CVE-2017-16148 vulnerability affects serve46, a static file server implementation that suffers from a critical directory traversal flaw. This vulnerability stems from inadequate input validation and path sanitization within the server's URL processing logic, allowing remote attackers to access arbitrary files on the underlying filesystem through crafted URL requests containing ../ sequences. The flaw represents a classic path traversal vulnerability that has been documented in numerous security frameworks and standards, including CWE-22 which specifically addresses "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')".
The technical implementation of this vulnerability occurs when the serve46 server fails to properly sanitize or canonicalize user-supplied URLs before resolving file paths. When an attacker submits a request containing directory traversal sequences such as "../", the server processes these sequences without proper validation, effectively allowing access to parent directories in the filesystem hierarchy. This creates a scenario where an attacker can navigate beyond the intended document root and potentially access sensitive system files, configuration data, or other restricted resources that should remain isolated from public access.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with the ability to extract sensitive information from the server's filesystem. An attacker could potentially access system configuration files, user credentials, application source code, database files, or other confidential data stored on the server. This vulnerability directly maps to ATT&CK technique T1083 which describes "File and Directory Discovery" and can be leveraged as part of a broader attack chain to escalate privileges or extract additional system information. The vulnerability also aligns with ATT&CK technique T1566 which covers "Phishing with Malicious Attachment" and can be used to deliver malicious payloads through compromised file access.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and path sanitization measures. The most effective approach involves canonicalizing all user-supplied paths and ensuring that the server never resolves paths that attempt to traverse above the intended document root directory. Implementing proper access controls through secure configuration of the web server, utilizing security headers, and applying regular security updates are essential defensive measures. Organizations should also consider implementing web application firewalls that can detect and block suspicious path traversal attempts, and conduct regular security assessments to identify and remediate similar vulnerabilities in other applications. The vulnerability demonstrates the critical importance of proper input validation and the principle of least privilege in secure system design, aligning with security best practices outlined in frameworks such as the OWASP Top Ten and NIST cybersecurity guidelines.