CVE-2001-0286 in HTTP Server
Summary
by MITRE
Directory traversal vulnerability in A1 HTTP server 1.0a allows remote attackers to read arbitrary files via a .. (dot dot) in an HTTP GET request.
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Analysis
by VulDB Data Team • 05/06/2025
The CVE-2001-0286 vulnerability represents a classic directory traversal flaw that affected the A1 HTTP server version 1.0a, demonstrating a fundamental security weakness in how web servers handle file path resolution. This vulnerability falls under the common weakness enumeration CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw occurs when an HTTP server fails to properly validate or sanitize user input that contains directory path references, allowing malicious actors to access files outside of the intended web root directory. The vulnerability is particularly dangerous because it enables attackers to exploit the server's file system access mechanisms through seemingly innocent HTTP GET requests.
The technical implementation of this vulnerability exploits the server's inability to properly process directory traversal sequences such as ".." or "%2e%2e" in file paths. When an attacker crafts an HTTP GET request containing these sequences, the server processes them without adequate validation, effectively allowing access to arbitrary files on the system. This occurs because the server does not properly resolve relative paths or implement proper input sanitization before accessing the file system. The attack vector is straightforward and requires minimal technical expertise, making it particularly dangerous as it can be exploited by attackers with basic knowledge of web protocols and file system structures. The vulnerability is classified as a remote attack vector since no local system access is required to exploit it.
The operational impact of CVE-2001-0286 extends beyond simple unauthorized file access, as it can lead to complete system compromise when combined with other attack techniques. An attacker who successfully exploits this vulnerability can access sensitive files such as configuration files, database files, system logs, and potentially even system binaries that contain critical information. The attack can result in data theft, system reconnaissance, and in some cases, privilege escalation if the server process has elevated permissions. This vulnerability aligns with the attack technique T1083 in the MITRE ATT&CK framework, which covers discovery of system information through file and directory enumeration. The vulnerability also relates to T1566, which covers credential access through exploitation of remote services, as the ability to read system files often reveals credentials stored in configuration files or log files.
Mitigation strategies for CVE-2001-0286 require immediate implementation of proper input validation and sanitization mechanisms. Organizations should implement proper path normalization techniques that prevent directory traversal sequences from being processed as legitimate file paths. The recommended approach includes implementing strict input validation that filters or rejects any request containing ".." sequences or similar path traversal indicators. Additionally, servers should be configured with proper access controls that limit the file system permissions of the web server process, ensuring that even if an attack succeeds, the damage is minimized. System administrators should also implement proper logging and monitoring to detect suspicious file access patterns that may indicate exploitation attempts. The vulnerability highlights the importance of following secure coding practices and implementing defense-in-depth strategies that include network segmentation, regular security updates, and comprehensive vulnerability management programs to prevent similar issues from occurring in modern web server implementations.