CVE-2001-0557 in Jana Web Server
Summary
by MITRE
T. Hauck Jana Webserver 1.46 and earlier allows a remote attacker to view arbitrary files via a .. (dot dot) attack which is URL encoded (%2e%2e).
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Analysis
by VulDB Data Team • 05/11/2025
The vulnerability described in CVE-2001-0557 represents a classic directory traversal flaw that affects the T. Hauck Jana Webserver version 1.46 and earlier. This security weakness stems from insufficient input validation within the web server's file handling mechanisms, allowing malicious actors to access files outside the intended web root directory through crafted URL requests. The vulnerability specifically exploits the lack of proper sanitization of directory path components, enabling attackers to navigate upward through the file system hierarchy using the conventional double dot notation.
The technical implementation of this vulnerability involves URL encoding of the directory traversal sequence where plain dot dot characters are replaced with %2e%2e. This encoding technique allows attackers to bypass basic input filters that might only check for literal .. sequences while still maintaining the malicious intent of the attack. When the web server processes these encoded requests, it fails to properly resolve the path components, leading to unauthorized file access. The flaw operates at the application layer and demonstrates poor input validation practices that are commonly categorized under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory.
From an operational standpoint, this vulnerability presents significant risks to systems running the affected web server version. An attacker could potentially access sensitive configuration files, user data, system credentials, or other confidential information stored on the server. The impact extends beyond simple information disclosure as it could enable further exploitation, including potential code execution if the attacker can access files containing executable code or if they can place malicious files in writable directories. The remote nature of this attack means that no local system access is required, making it particularly dangerous for publicly accessible web servers.
The security implications of this vulnerability align with ATT&CK technique T1083, which covers directory and file discovery activities, and T1566, which addresses credential access through various attack vectors. Organizations running affected web server versions should immediately implement mitigations including patching to the latest available version, implementing proper input validation at the application level, and configuring web server restrictions to prevent traversal attacks. Additional protective measures include deploying web application firewalls that can detect and block suspicious path traversal patterns, implementing proper access controls, and conducting regular security assessments to identify similar vulnerabilities in other web applications and server configurations.