CVE-1999-0985 in Whois
Summary
by MITRE
CC 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 • 07/03/2024
The vulnerability described in CVE-1999-0985 represents a critical command injection flaw within the CC Whois program's whois.cgi component that was prevalent in the late 1990s era of internet infrastructure. This vulnerability falls under the CWE-77 category of Command Injection, where the software directly incorporates user-supplied data into shell commands without proper sanitization or validation. The specific implementation flaw occurred in the whois.cgi script that processed domain name queries, allowing remote attackers to manipulate the input parameters through shell metacharacters such as semicolons, ampersands, or backticks that would be interpreted by the underlying shell executing the command.
The operational impact of this vulnerability was severe and far-reaching across the internet infrastructure landscape of the time. Attackers could exploit this weakness to execute arbitrary commands on systems running vulnerable versions of the CC Whois software, potentially gaining unauthorized access to sensitive system information, modifying system files, or even establishing persistent backdoors. The vulnerability was particularly dangerous because it leveraged the inherent trust placed in whois lookup functionality, which was commonly used by network administrators and security professionals for legitimate purposes. This made exploitation more likely and the attack surface broader since whois services were frequently accessed and often run with elevated privileges to perform system queries.
The technical exploitation of this vulnerability demonstrated a classic example of insufficient input validation and improper output encoding in web applications, which aligns with the ATT&CK framework's T1059.001 technique for command and script injection. The flaw exploited the lack of proper sanitization of user input before being passed to shell execution functions, creating a direct path for attackers to bypass normal access controls and execute malicious commands with the privileges of the web server process. This vulnerability was particularly concerning because it could be exploited through simple web interface interactions without requiring sophisticated attack techniques or specialized tools, making it a prime target for automated exploitation scripts.
Organizations and system administrators needed to implement immediate mitigations including input validation and sanitization of all user-supplied data, proper escaping of shell metacharacters, and limiting the privileges under which whois services operated. The recommended approaches included implementing proper parameter validation, using safe shell execution functions that do not interpret metacharacters, and ensuring that whois services ran with minimal required privileges. This vulnerability highlighted the critical importance of input validation in web applications and contributed to the evolution of security practices that would later be codified in various security standards and frameworks. The incident underscored the necessity of following secure coding practices and demonstrated how seemingly benign services could become attack vectors when proper security controls were not implemented.