CVE-2002-0433 in Pi3Web
Summary
by MITRE
Pi3Web 2.0.0 allows remote attackers to view restricted files via an HTTP request containing a "*" (wildcard or asterisk) character.
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Analysis
by VulDB Data Team • 09/17/2025
The vulnerability described in CVE-2002-0433 represents a critical access control flaw in Pi3Web version 2.0.0, a web server software that was widely used during the early 2000s. This issue stems from improper input validation and path traversal mechanisms within the web server's file access handling. The vulnerability specifically manifests when a remote attacker crafts an HTTP request containing a wildcard character asterisk "*", which the server processes incorrectly, leading to unauthorized access to files that should be restricted or protected. This type of vulnerability falls under the category of improper access control as defined by CWE-284, where the system fails to properly enforce access restrictions. The flaw demonstrates a classic path traversal vulnerability where the web server's interpretation of the wildcard character bypasses normal file system access controls.
The technical implementation of this vulnerability occurs at the HTTP request parsing level where the Pi3Web server fails to sanitize or properly validate the wildcard character in file path requests. When the server encounters a request containing "*", it likely interprets this as a legitimate path specification rather than a malicious attempt to traverse directories. This processing error creates a condition where the web server's internal file resolution mechanism allows access to files outside of the intended web root directory. The vulnerability is particularly concerning because it requires minimal effort from an attacker to exploit, as they only need to construct a simple HTTP request with the wildcard character to potentially access sensitive system files, configuration data, or other restricted resources. This behavior aligns with ATT&CK technique T1071.004 for application layer protocol manipulation and T1566 for malicious file execution through web applications.
The operational impact of this vulnerability extends beyond simple unauthorized file access, potentially exposing sensitive system information that could aid in further exploitation attempts. Attackers could leverage this vulnerability to access server configuration files, application source code, database connection details, or other critical system information that would otherwise be protected. The exposure of such information could lead to privilege escalation, system compromise, or data breaches. Organizations running Pi3Web 2.0.0 were particularly vulnerable because the software was designed without proper input validation mechanisms to prevent such wildcard character interpretation. This vulnerability represents a fundamental flaw in the web server's security architecture where the lack of proper path validation and access control enforcement creates an exploitable condition that can be leveraged by remote attackers without requiring authentication or special privileges.
Mitigation strategies for this vulnerability should focus on immediate software updates and patches provided by the vendor, as well as implementing proper input validation measures. Organizations should ensure that all web server software is kept up to date with the latest security patches and that wildcard character handling is properly sanitized in HTTP request processing. Network-level mitigations such as web application firewalls can help detect and block malformed requests containing wildcard characters, while proper access control configurations should be implemented to limit file system access even if the vulnerability is exploited. The vulnerability also underscores the importance of secure coding practices and input validation, particularly for web applications handling file system operations. Regular security assessments and penetration testing should be conducted to identify similar path traversal vulnerabilities in other web server implementations and ensure that proper security controls are in place to prevent unauthorized access to restricted system resources.