CVE-1999-0984 in Whois
Summary
by MITRE
Matt's Whois program whois.cgi allows remote attackers to execute commands via shell metacharacters in the domain entry.
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Analysis
by VulDB Data Team • 04/19/2026
The vulnerability identified as CVE-1999-0984 resides within the Matt s Whois program whois.cgi component, representing a critical security flaw that enables remote attackers to execute arbitrary commands on the affected system. This issue stems from insufficient input validation and improper sanitization of user-supplied data within the web-based whois interface. The vulnerability specifically manifests when the domain entry parameter contains shell metacharacters that are not properly escaped or filtered, allowing attackers to inject malicious commands that get executed by the underlying shell processes. This type of vulnerability falls under the category of command injection attacks and aligns with CWE-77 which defines improper neutralization of special elements used in a command.
The technical exploitation of this vulnerability occurs through the manipulation of the whois.cgi script's input handling mechanism. When users submit domain queries through the web interface, the application fails to properly sanitize the input before passing it to system commands. Attackers can leverage this weakness by embedding shell metacharacters such as semicolons, ampersands, or backticks within the domain name field, which then get interpreted by the shell and executed with the privileges of the web server process. The operational impact of this vulnerability is severe as it can lead to complete system compromise, allowing attackers to execute arbitrary code, access sensitive data, modify system files, and potentially establish persistent backdoors.
This vulnerability demonstrates a classic example of insecure input handling and highlights the importance of proper command construction and argument sanitization in web applications. The attack vector operates through standard web browser interactions, making it accessible to attackers without requiring specialized tools or deep technical knowledge of the underlying system. From an operational perspective, the vulnerability can result in unauthorized access to system resources, data breaches, and potential lateral movement within network environments. Organizations running affected versions of the Matt s Whois program are particularly at risk since the vulnerability allows for remote code execution without authentication requirements, making it an attractive target for automated exploitation.
The mitigation strategies for this vulnerability involve multiple layers of defense including immediate patching of the affected software, implementing proper input validation and sanitization mechanisms, and applying web application firewalls to filter malicious payloads. Security professionals should ensure that all user inputs are properly escaped or encoded before being passed to system commands, following the principle of least privilege for web server processes. Additionally, implementing proper output encoding and input validation techniques can prevent the exploitation of similar command injection vulnerabilities. This vulnerability also emphasizes the importance of regular security assessments and vulnerability scanning to identify and remediate such flaws before they can be exploited by malicious actors. The attack pattern aligns with ATT&CK technique T1059 which covers command and scripting interpreters, specifically targeting the execution of system commands through web interfaces and scripts.