CVE-2000-0920 in Webserver
Summary
by MITRE
Directory traversal vulnerability in BOA web server 0.94.8.2 and earlier allows remote attackers to read arbitrary files via a modified .. (dot dot) attack in the GET HTTP request that uses a "%2E" instead of a "."
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Analysis
by VulDB Data Team • 10/12/2025
The vulnerability described in CVE-2000-0920 represents a critical directory traversal flaw within the BOA web server version 09482 and earlier releases. This security weakness stems from inadequate input validation mechanisms that fail to properly sanitize HTTP GET requests containing directory traversal sequences. The specific exploitation technique involves substituting standard dot-dot sequences with URL-encoded equivalents, specifically utilizing "%2E" characters instead of conventional "." characters in the malicious payload. This particular variant demonstrates the sophistication of attackers who seek to bypass basic security filters by employing encoded character sequences that can evade simple pattern matching defenses.
The technical implementation of this vulnerability operates through the web server's file access mechanisms, where the BOA server fails to adequately normalize or validate incoming URI paths before processing file requests. When a malicious request containing "%2E%2E%2F" sequences is received, the server processes these encoded characters without proper sanitization, allowing an attacker to navigate through the file system hierarchy beyond the intended web root directory. This flaw directly maps to CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal or Directory Traversal. The vulnerability essentially allows attackers to bypass normal file access controls and retrieve arbitrary files from the server's file system, potentially exposing sensitive information such as configuration files, password databases, or other confidential data stored on the server.
The operational impact of this vulnerability extends far beyond simple information disclosure, as it provides attackers with the capability to access critical system resources that should remain protected from unauthorized access. Remote exploitation of this flaw means that an attacker can potentially retrieve system files, user credentials, application source code, or other sensitive data without requiring any local system access or authentication. This represents a severe privilege escalation vector that can lead to complete system compromise when combined with other vulnerabilities or when the exposed files contain sensitive configuration information. The vulnerability affects the fundamental security model of the web server by allowing unauthorized file access through what should be legitimate HTTP requests, fundamentally undermining the server's ability to maintain proper access controls. Organizations running affected versions of BOA web server face significant risk of data breaches, system compromise, and regulatory compliance violations when this vulnerability remains unpatched.
Mitigation strategies for CVE-2000-0920 should prioritize immediate patching of affected BOA web server installations to the latest available versions that contain proper input validation and sanitization mechanisms. System administrators should implement comprehensive web application firewalls that can detect and block suspicious URL-encoded sequences, particularly those containing multiple encoded dot-dot combinations. Network segmentation and access control measures should be strengthened to limit exposure of vulnerable web servers to untrusted networks. Additionally, regular security audits should verify that all web server configurations properly implement directory traversal protection mechanisms and that input validation is consistently applied to all HTTP request parameters. The vulnerability also highlights the importance of implementing proper security monitoring and logging to detect anomalous access patterns that may indicate attempted exploitation, as outlined in the ATT&CK framework's technique T1213 for Data from Information Repositories. Organizations should also consider implementing automated vulnerability scanning tools that can identify similar directory traversal vulnerabilities in other web applications and services within their infrastructure.