CVE-2001-0022 in simplestguest.cgi
Summary
by MITRE
simplestguest.cgi CGI program by Leif Wright allows remote attackers to execute arbitrary commands via shell metacharacters in the guestbook parameter.
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Analysis
by VulDB Data Team • 07/21/2024
The vulnerability identified as CVE-2001-0022 affects the simplestguest.cgi CGI program developed by Leif Wright, representing a classic example of command injection in web applications. This flaw exists within the guestbook parameter processing functionality of the CGI script, where user input is directly incorporated into system commands without proper sanitization or validation. The vulnerability stems from the program's failure to properly escape or filter special shell metacharacters, creating an avenue for malicious actors to execute arbitrary commands on the underlying system. This type of vulnerability falls under the category of CWE-78, which specifically addresses improper neutralization of special elements used in OS commands, making it a fundamental security weakness in command execution contexts.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious payload containing shell metacharacters such as semicolons, pipes, or backticks within the guestbook parameter. When the CGI script processes this input, it passes the unfiltered data directly to the operating system shell, allowing the attacker to append additional commands that execute with the privileges of the web server process. The impact of such exploitation can be severe, potentially enabling attackers to gain full system control, access sensitive data, modify files, or even establish persistent backdoors. This vulnerability demonstrates the critical importance of input validation and proper command construction in web applications, as it represents a direct pathway to system compromise through improper handling of user-supplied data.
From an operational perspective, this vulnerability creates significant risk for organizations running the affected CGI program, as it provides remote attackers with a straightforward method for system compromise. The attack surface is relatively narrow since it requires access to the specific CGI endpoint, but the potential impact is substantial given that successful exploitation typically results in complete system compromise. The vulnerability's exploitation aligns with ATT&CK technique T1059.001, which covers command and scripting interpreter execution, and T1068, which addresses exploit for privilege escalation. Organizations must recognize that this vulnerability exists in legacy software environments where proper input validation was not yet standard practice, highlighting the importance of maintaining up-to-date security measures and proper code review processes.
The remediation approach for CVE-2001-0022 requires immediate implementation of proper input validation and sanitization mechanisms. System administrators should ensure that all user-supplied input is properly escaped or filtered before being used in system command contexts. The recommended solution involves implementing proper parameter validation, using safe APIs for command execution, and avoiding direct shell command construction with user input. Organizations should also consider migrating away from legacy CGI implementations toward more modern web application frameworks that provide built-in protection against such vulnerabilities. Additionally, implementing proper access controls and network segmentation can help limit the potential impact of successful exploitation attempts. The vulnerability underscores the critical need for security awareness training and code review practices that emphasize proper input handling and command execution security principles.