CVE-2017-16134 in http_static_simple
Summary
by MITRE
http_static_simple is an http server. http_static_simple 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 vulnerability identified as CVE-2017-16134 affects http_static_simple, a lightweight http server implementation that serves static content. This particular server lacks proper input validation mechanisms for URL path handling, creating a critical security flaw that allows unauthorized access to the underlying file system. The vulnerability stems from the server's inability to properly sanitize or normalize file paths received in HTTP requests, enabling attackers to manipulate URL parameters to navigate beyond the intended document root directory.
The technical flaw manifests through a classic directory traversal attack vector where malicious actors can append ../ sequences to file paths in URLs to move up the directory hierarchy. This weakness directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. When http_static_simple processes these manipulated URLs, it fails to validate or sanitize the input, allowing the server to interpret and serve files from arbitrary locations on the file system. The attack requires minimal sophistication as it exploits the fundamental lack of input validation in the server's path resolution logic.
The operational impact of this vulnerability is severe and multifaceted, potentially exposing sensitive system files, configuration data, and user information to unauthorized access. An attacker could leverage this vulnerability to read system files such as password hashes, configuration files containing database credentials, or application source code that might contain additional vulnerabilities. The compromise extends beyond simple information disclosure to potentially enable further attack vectors including privilege escalation, data exfiltration, or system compromise. This vulnerability is particularly dangerous in environments where the http_static_simple server is running with elevated privileges or has access to sensitive directories.
Mitigation strategies for CVE-2017-16134 should focus on implementing proper input validation and path normalization within the http_static_simple server implementation. Organizations should ensure that all URL paths are properly sanitized before being processed, with special characters like ../ being explicitly rejected or normalized to prevent directory traversal attempts. The server should implement strict path validation that ensures all requested paths remain within the designated document root directory. Additionally, this vulnerability aligns with ATT&CK technique T1083, which covers the discovery of system information through directory listing and file enumeration. System administrators should also consider implementing network-level protections such as web application firewalls that can detect and block suspicious path traversal patterns, while also ensuring that the server runs with minimal required privileges to limit potential damage from successful exploitation attempts.