CVE-2017-16094 in iter-http
Summary
by MITRE
iter-http is a server for static files. iter-http 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 • 02/15/2020
The vulnerability identified as CVE-2017-16094 affects iter-http, a server designed for serving static files over HTTP. This particular implementation suffers from a critical directory traversal flaw that fundamentally compromises the security boundaries of the web server. The vulnerability stems from insufficient input validation and path sanitization within the server's request handling mechanism, allowing malicious actors to exploit the system's file access controls through simple URL manipulation techniques.
The technical flaw manifests when the iter-http server fails to properly sanitize user-supplied URL parameters before resolving file paths. Attackers can exploit this weakness by injecting ../ sequences into URLs, which effectively navigates up directory levels in the file system hierarchy. This directory traversal technique allows unauthorized access to files and directories that should remain protected within the server's designated document root. The vulnerability operates at the application layer and can be exploited through standard HTTP requests without requiring elevated privileges or specialized tools.
The operational impact of this vulnerability is severe and far-reaching for any system running the affected iter-http server. An attacker who successfully exploits this directory traversal flaw can access sensitive files including configuration files, database files, source code repositories, and potentially system credentials stored within the file system. The exposure extends beyond simple file access to include potential privilege escalation scenarios, especially if the server process runs with elevated permissions. This vulnerability directly violates the principle of least privilege and undermines the fundamental security model of web server implementations.
Organizations utilizing iter-http should immediately implement mitigations including input validation, path normalization, and proper access control enforcement. The most effective immediate fix involves implementing strict path validation that prevents traversal sequences from being processed, ensuring that all file access requests are validated against a whitelist of acceptable paths. Additionally, the server should be configured to run with minimal required privileges and implement proper file system access controls. This vulnerability aligns with CWE-22 Directory Traversal and maps to ATT&CK technique T1083 File and Directory Discovery, emphasizing the need for comprehensive security controls. System administrators should also consider implementing web application firewalls and monitoring for suspicious URL patterns that may indicate exploitation attempts.