CVE-2002-0434 in Directory
Summary
by MITRE
Marcus S. Xenakis directory.php script allows remote attackers to execute arbitrary commands via shell metacharacters in the dir parameter.
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Analysis
by VulDB Data Team • 05/13/2019
The vulnerability identified as CVE-2002-0434 represents a critical command injection flaw in the directory.php script developed by Marcus S. Xenakis. This security weakness resides in the script's improper handling of user input parameters, specifically the dir parameter that is processed without adequate sanitization or validation. The vulnerability falls under the category of CWE-77 which defines improper neutralization of special elements used in a command shell, making it a prime example of command injection attacks that have plagued web applications for decades. The flaw enables malicious actors to execute arbitrary system commands on the affected server by manipulating the dir parameter through shell metacharacters such as semicolons, ampersands, or backticks that are interpreted by the underlying operating system shell.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious input string containing shell metacharacters and passes it through the dir parameter to the vulnerable directory.php script. The script fails to properly validate or sanitize this input before using it in system calls or shell execution contexts. When the web application processes this malicious input, the shell interprets the injected metacharacters as command separators or operators, effectively allowing the attacker to execute arbitrary commands with the privileges of the web server process. This type of vulnerability is particularly dangerous because it can provide attackers with complete control over the affected system, potentially enabling them to access sensitive data, install backdoors, or launch further attacks against the network infrastructure.
The operational impact of CVE-2002-0434 extends beyond simple command execution, as it fundamentally compromises the integrity and confidentiality of the affected system. Attackers can leverage this vulnerability to perform reconnaissance activities, escalate privileges, and establish persistent access points within the network. The vulnerability's classification under the ATT&CK framework would place it in the Command and Control domain, specifically under techniques such as Command and Scripting Interpreter where adversaries use system shells to execute commands. Organizations running vulnerable versions of the directory.php script face significant risk of data breaches, system compromise, and potential regulatory violations, particularly in environments where the web application processes sensitive information or operates in regulated industries.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements. The primary solution involves implementing proper input validation and sanitization mechanisms that filter out or escape special shell metacharacters before processing user input. Organizations should adopt parameterized interfaces or secure coding practices that prevent shell command construction from user-supplied data. Additionally, the principle of least privilege should be enforced by running web server processes with minimal required permissions and implementing proper access controls. The vulnerability demonstrates the critical importance of input validation and output encoding practices as outlined in the OWASP Top Ten security framework, and organizations should consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts. Regular security assessments and code reviews should be conducted to identify similar patterns of insecure coding practices that could lead to command injection vulnerabilities in other parts of the application stack.