CVE-2002-0112 in EServ
Summary
by MITRE
Etype Eserv 2.97 allows remote attackers to view password protected files via /./ in the URL.
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Analysis
by VulDB Data Team • 09/22/2025
The vulnerability identified as CVE-2002-0112 affects Etype Eserv 2.97, a web server software that was widely used in the early 2000s for hosting web content and managing file access. This particular flaw represents a directory traversal attack vector that exploits improper input validation within the web server's URL parsing mechanism. The vulnerability specifically manifests when attackers manipulate URL paths using the sequence /./ which should theoretically be normalized by web servers to prevent access to parent directories. However, Eserv 2.97 fails to properly sanitize these paths, allowing malicious users to bypass authentication mechanisms and access password-protected files that should otherwise remain restricted.
The technical exploitation of this vulnerability occurs through the manipulation of Uniform Resource Locators containing the forward slash followed by a period and another forward slash sequence. When the web server processes such URLs, it does not correctly interpret the /./ component as a request to remain in the current directory, instead allowing the traversal to proceed past expected boundaries. This flaw directly relates to CWE-22, known as "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", which is a fundamental security weakness in file system access controls. The vulnerability essentially allows an attacker to craft URLs that appear to reference files within protected directories, but the server fails to properly validate these paths against the intended access controls.
The operational impact of CVE-2002-0112 is significant as it fundamentally undermines the authentication and authorization mechanisms that protect sensitive data within the web server environment. Attackers can leverage this vulnerability to access files that contain confidential information, user credentials, configuration data, or other sensitive materials that should be protected by password authentication. This represents a critical bypass of security controls that are essential for maintaining data confidentiality and integrity. The vulnerability affects the core security model of the web server, potentially allowing unauthorized access to entire directory structures that should remain protected. Organizations using Eserv 2.97 were particularly vulnerable as this flaw could be exploited remotely without requiring any special privileges or credentials beyond basic internet connectivity.
Mitigation strategies for this vulnerability involve implementing proper input validation and path normalization within the web server software. The most effective approach is to upgrade to a newer version of Eserv that properly handles directory traversal attempts and normalizes URL paths before processing them. System administrators should also implement additional security measures such as restricting access to sensitive directories, configuring proper access control lists, and implementing web application firewalls that can detect and block suspicious URL patterns. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access through path traversal attacks, specifically targeting the T1078 credential access sub-technique. Organizations should also consider implementing network segmentation, regular security audits, and monitoring for unusual access patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and path handling in web applications, as highlighted by the CWE classification and the fundamental security principles surrounding directory traversal prevention.