CVE-2002-0531 in EMU
Summary
by MITRE
Directory traversal vulnerability in emumail.cgi in EMU Webmail 4.5.x and 5.1.0 allows remote attackers to read arbitrary files or list arbitrary directories via a .. (dot dot) in the type parameter.
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Analysis
by VulDB Data Team • 09/16/2025
The vulnerability described in CVE-2002-0531 represents a classic directory traversal flaw that existed in EMU Webmail versions 4.5.x and 5.1.0. This issue specifically affects the emumail.cgi script which processes user input through the type parameter. The vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly restrict file path access. Attackers can exploit this weakness by manipulating the type parameter with directory traversal sequences such as .. to navigate outside the intended directory structure and access unauthorized files or directories. This flaw operates at the application layer and demonstrates a fundamental failure in secure coding practices where user-supplied data directly influences file system operations without proper sanitization.
The technical implementation of this vulnerability falls under CWE-22, which categorizes it as a directory traversal or path traversal attack. The flaw allows attackers to perform unauthorized file access by manipulating the type parameter through dot-dot-slash sequences that traverse up the directory hierarchy. This type of vulnerability is particularly dangerous because it can be exploited to read system files, configuration data, or sensitive information that should remain protected. The attack vector is remote, meaning no local system access is required, and the impact extends beyond simple information disclosure to potentially enabling further exploitation. The vulnerability exists in the input processing logic where the application fails to validate or sanitize user-provided paths before using them in file operations.
From an operational standpoint, this vulnerability presents significant risk to organizations using affected EMU Webmail versions as it allows attackers to potentially access sensitive data stored on the web server. The exploitation can lead to unauthorized access to configuration files, user credentials, or other system information that could be used for privilege escalation or additional attacks. The vulnerability also enables directory listing capabilities, which can provide attackers with insights into the server's file structure and potentially reveal other vulnerable components. This issue can be leveraged as an initial foothold for more comprehensive attacks and represents a critical security gap in the web application's access control mechanisms. The remote nature of the attack means that organizations are vulnerable to exploitation from anywhere on the internet without requiring physical access to the system.
Mitigation strategies for this vulnerability should include immediate patching of the affected EMU Webmail versions to address the directory traversal flaw. Organizations should implement proper input validation and sanitization techniques to prevent unauthorized path traversal attempts. The application should validate all user-supplied input and reject any attempts to traverse directories using sequences such as .. or similar path manipulation techniques. Additionally, implementing proper access controls and least privilege principles can limit the damage from successful exploitation attempts. System administrators should also consider implementing web application firewalls or intrusion prevention systems that can detect and block suspicious path traversal attempts. The vulnerability highlights the importance of following secure coding practices and input validation standards, with recommendations aligning with the ATT&CK framework's defense-in-depth approach to prevent such exploitation techniques from succeeding.