CVE-2009-1916 in DNS Tools
Summary
by MITRE
dig.php in GScripts.net DNS Tools allows remote attackers to execute arbitrary commands via shell metacharacters in the ns parameter.
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Analysis
by VulDB Data Team • 11/27/2024
The vulnerability identified as CVE-2009-1916 resides within the dig.php script of GScripts.net DNS Tools, representing a critical command injection flaw that enables remote attackers to execute arbitrary system commands on the affected server. This vulnerability specifically targets the ns parameter handling within the dig.php file, which processes DNS lookup requests through the dig command-line utility. The flaw occurs when user-supplied input containing shell metacharacters is directly passed to the system command without proper sanitization or validation, creating an environment where malicious actors can inject and execute arbitrary commands with the privileges of the web application process.
The technical implementation of this vulnerability follows a classic command injection pattern where the application constructs system commands by concatenating user input directly into shell execution contexts. When an attacker submits a malicious ns parameter containing shell metacharacters such as semicolons, ampersands, or backticks, these characters are interpreted by the underlying shell, allowing the attacker to chain additional commands beyond the intended dig functionality. This type of vulnerability falls under CWE-77 which specifically addresses command injection flaws, and it aligns with ATT&CK technique T1059.001 for command and scripting interpreter, demonstrating how attackers can leverage web applications to execute system commands.
The operational impact of this vulnerability is severe and encompasses multiple attack vectors that can compromise the entire server infrastructure. An attacker could potentially gain full system access, execute arbitrary code, escalate privileges, and perform data exfiltration or destruction. The vulnerability affects not just the specific DNS lookup functionality but represents a fundamental security flaw that could allow attackers to pivot to other systems within the network, especially if the web application runs with elevated privileges. The remote nature of this exploit means that attackers do not require physical access or prior authentication to the system, making it particularly dangerous for publicly accessible web applications.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security architecture improvements. The primary fix involves implementing proper input validation and sanitization of all user-supplied parameters, specifically ensuring that the ns parameter does not contain any shell metacharacters or command separators. Applications should employ parameterized command execution where possible, avoiding direct shell command construction from user input. Additionally, implementing proper privilege separation by running web applications with minimal required privileges, utilizing input whitelisting for DNS server names, and employing secure coding practices that prevent command injection vulnerabilities. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for suspicious command execution patterns, while conducting regular security assessments to identify similar vulnerabilities in other components of the application stack.