CVE-2002-1750 in csGuestbook
Summary
by MITRE
csGuestbook.cgi in CGISCRIPT.NET csGuestbook 1.0 allows remote attackers to execute arbitrary Perl code via the setup parameter, which is processed by the Perl eval function.
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Analysis
by VulDB Data Team • 03/14/2017
The vulnerability identified as CVE-2002-1750 resides within the csGuestbook.cgi script distributed by CGISCRIPT.NET version 1.0, representing a critical server-side code execution flaw that fundamentally compromises web application security. This vulnerability specifically targets the guestbook application's handling of user input through the setup parameter, which is processed using Perl's eval function without proper sanitization or validation. The flaw constitutes a classic command injection vulnerability where attacker-controlled input directly influences the Perl interpreter's execution flow, enabling unauthorized remote code execution on the affected server.
The technical implementation of this vulnerability stems from the improper handling of user-supplied parameters within the CGI script's configuration setup functionality. When the setup parameter is submitted to csGuestbook.cgi, the application directly passes this input to Perl's eval function without any input validation, sanitization, or escaping mechanisms. This design flaw aligns with CWE-94, which describes the weakness of executing arbitrary code or commands, and specifically manifests as an improper input validation issue that allows attackers to inject malicious Perl code. The eval function in Perl executes code dynamically, making it particularly dangerous when fed untrusted input, as it effectively bypasses normal code execution boundaries and allows complete system compromise.
Operationally, this vulnerability presents severe implications for system administrators and security practitioners as it enables remote attackers to execute arbitrary commands on the web server with the privileges of the web application process. Attackers can leverage this flaw to gain unauthorized access to the server, potentially escalating privileges, exfiltrating sensitive data, installing backdoors, or using the compromised system as a launch point for further attacks within the network infrastructure. The vulnerability's remote exploitability means that attackers need only access to the web application's URL to execute malicious code, making it particularly attractive for automated exploitation campaigns. This represents a direct violation of the principle of least privilege and provides attackers with a powerful foothold for lateral movement and persistent access.
The security implications extend beyond immediate code execution to encompass broader system compromise and data integrity violations. Given that the vulnerability allows full command execution capabilities, attackers can manipulate the web server environment, modify or delete files, access databases, and potentially establish persistent access through various attack vectors. Organizations using this vulnerable software face significant risk of data breaches, system compromise, and potential regulatory violations depending on the nature of data processed by the affected applications. The vulnerability's exploitation aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically targeting Perl interpreter execution, and represents a critical weakness in the application's input handling that violates fundamental security principles.
Mitigation strategies for CVE-2002-1750 require immediate remediation through software updates or patches provided by the vendor, as the vulnerability is inherent to the application's design and cannot be effectively mitigated through network-level controls alone. Organizations should implement input validation and sanitization measures, including proper parameter validation, escaping of special characters, and avoidance of dynamic code execution functions like eval when processing user input. Additionally, implementing web application firewalls, restricting file permissions, and conducting regular security assessments can help reduce the attack surface and prevent exploitation. The vulnerability demonstrates the critical importance of secure coding practices and input validation, particularly in legacy applications that may not have been designed with modern security considerations in mind.