CVE-2000-0913 in HTTP Server
Summary
by MITRE
mod_rewrite in Apache 1.3.12 and earlier allows remote attackers to read arbitrary files if a RewriteRule directive is expanded to include a filename whose name contains a regular expression.
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Analysis
by VulDB Data Team • 05/20/2019
The vulnerability described in CVE-2000-0913 represents a critical security flaw in the Apache HTTP Server's mod_rewrite module affecting versions 1.3.12 and earlier. This issue stems from improper input validation within the rewrite engine's handling of regular expression patterns in RewriteRule directives. The flaw allows remote attackers to exploit the module's expansion mechanism to access arbitrary files on the server, potentially leading to unauthorized data disclosure and system compromise. The vulnerability specifically manifests when a RewriteRule directive contains a filename pattern that includes regular expression metacharacters, enabling attackers to manipulate the rewrite process to read files outside the intended scope.
The technical root cause of this vulnerability lies in the mod_rewrite module's insufficient sanitization of user-supplied input within rewrite rules. When a RewriteRule directive is processed, the module expands regular expression patterns without adequate validation of the resulting filename components. This behavior creates a path traversal condition where attackers can craft malicious rewrite rules that, when processed, expand to include arbitrary file paths. The vulnerability operates at the application layer and can be exploited through HTTP requests that contain specially crafted rewrite directives, making it particularly dangerous as it can be triggered remotely without requiring authentication or special privileges.
The operational impact of CVE-2000-0913 extends beyond simple information disclosure to potentially enable complete system compromise. An attacker who successfully exploits this vulnerability can read sensitive files such as configuration files, database credentials, user information, and other confidential data stored on the server. The attack vector is particularly concerning because it can be executed through standard web requests, making it difficult to detect and prevent. This vulnerability aligns with CWE-22 Path Traversal and CWE-23 Improper Limitation of a Pathname to a Restricted Directory, both of which are categorized under the broader class of path traversal attacks that have been consistently ranked among the top security risks in industry standards and frameworks.
Security professionals should recognize this vulnerability as a prime example of how seemingly benign functionality can become a critical attack surface when proper input validation is absent. The flaw demonstrates the importance of principle of least privilege and proper access control implementation within web server modules. Organizations should immediately upgrade to Apache 1.3.13 or later versions where this vulnerability has been patched, as the fix involves proper sanitization of regular expression patterns within rewrite directives. Additionally, implementing web application firewalls and input validation mechanisms can provide additional layers of protection against similar attacks. This vulnerability serves as a historical reminder of the critical importance of secure coding practices in server-side components and the potential consequences of inadequate input validation in widely deployed software components. The attack pattern associated with this vulnerability would be classified under ATT&CK technique T1059 Command and Scripting Interpreter and T1566 Impersonation of a Trusted User, as it enables unauthorized access to system resources through manipulation of server configuration.