CVE-2000-0421 in Bugzilla
Summary
by MITRE
The process_bug.cgi script in Bugzilla allows remote attackers to execute arbitrary commands via shell metacharacters.
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Analysis
by VulDB Data Team • 10/16/2025
The CVE-2000-0421 vulnerability represents a critical command injection flaw in the Bugzilla bug tracking system's process_bug.cgi script. This vulnerability arises from insufficient input validation and sanitization within the web application's processing logic, creating an exploitable pathway for remote attackers to execute arbitrary system commands on the affected server. The flaw specifically manifests when user-supplied input containing shell metacharacters is improperly handled and directly passed to system execution functions without adequate filtering or escaping mechanisms.
The technical implementation of this vulnerability stems from the script's failure to properly sanitize user input before incorporating it into shell command executions. When an attacker crafts malicious input containing special shell characters such as semicolons, pipes, or backticks, these metacharacters can be interpreted by the underlying shell, allowing the attacker to append and execute additional commands beyond the intended functionality. This represents a classic command injection vulnerability that falls under the CWE-77 category, specifically classified as "Improper Neutralization of Special Elements used in a Command ('Command Injection')". The vulnerability is particularly dangerous because it allows attackers to gain arbitrary code execution privileges on the server hosting the Bugzilla instance, potentially leading to full system compromise.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the capability to escalate privileges, exfiltrate sensitive data, modify system configurations, or establish persistent access points within the network. Attackers can leverage this vulnerability to perform reconnaissance activities, access confidential bug reports and user information, or even deploy malware on the compromised system. The vulnerability affects organizations using Bugzilla versions prior to 2.17.4, making it particularly concerning for legacy systems that may not have received timely security updates. From an ATT&CK framework perspective, this vulnerability maps to techniques such as T1059.001 (Command and Scripting Interpreter: Shell Script) and T1068 (Exploitation for Privilege Escalation), demonstrating how a single input validation flaw can enable multiple attack vectors.
Mitigation strategies for CVE-2000-0421 primarily focus on immediate remediation through software updates and input validation hardening. Organizations should prioritize upgrading to Bugzilla version 2.17.4 or later, which includes proper input sanitization measures. Additionally, implementing proper input validation and output encoding techniques can prevent malicious metacharacters from being interpreted by the shell. Security measures should include disabling unnecessary system command execution capabilities, implementing proper access controls, and deploying web application firewalls to detect and block suspicious input patterns. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other applications, as command injection flaws often occur in web applications that handle user input and execute system commands. The vulnerability also highlights the importance of following secure coding practices, particularly the principle of least privilege, where applications should execute with minimal necessary permissions to reduce potential impact of such exploits.