CVE-2005-1351 in ad.cgi
Summary
by MITRE
The ad.cgi script allows remote attackers to execute arbitrary commands via shell metacharacters in the argument.
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Analysis
by VulDB Data Team • 07/05/2021
The vulnerability described in CVE-2005-1351 represents a critical command injection flaw in the ad.cgi script that operates within web applications. This issue stems from inadequate input validation and sanitization mechanisms within the script's parameter handling process. The vulnerability is classified under CWE-77 which specifically addresses improper neutralization of special elements used in a command inside a software platform. The ad.cgi script fails to properly filter or escape user-supplied arguments before incorporating them into system commands, creating a pathway for malicious actors to inject and execute arbitrary commands on the underlying operating system.
The technical exploitation of this vulnerability occurs when remote attackers craft malicious input containing shell metacharacters such as semicolons, ampersands, or backticks within the script's argument parameters. These metacharacters are interpreted by the shell as command separators or operators, allowing attackers to append additional commands that execute with the privileges of the web server process. The flaw typically manifests when the script passes user input directly to system functions without proper sanitization, enabling attackers to bypass authentication mechanisms and gain unauthorized access to system resources. This type of vulnerability falls under the ATT&CK technique T1059.001 for Command and Scripting Interpreter, specifically targeting the use of shell commands within web applications.
The operational impact of this vulnerability extends far beyond simple command execution, as it provides attackers with potential access to sensitive system information, file manipulation capabilities, and the ability to establish persistent backdoors. An attacker could leverage this vulnerability to escalate privileges, access confidential data, or even compromise the entire server infrastructure. The vulnerability is particularly dangerous because it requires minimal technical expertise to exploit, making it a popular target for automated attack tools and script kiddies. Additionally, the impact is amplified when the web server runs with elevated privileges, potentially allowing full system compromise rather than just web application level access.
Mitigation strategies for CVE-2005-1351 must focus on implementing robust input validation and sanitization mechanisms within the affected application. The primary defense involves proper escaping or encoding of all user-supplied input before processing, ensuring that shell metacharacters are treated as literal characters rather than command operators. Organizations should implement whitelisting approaches for acceptable input parameters and avoid direct system command invocation with user data. The use of secure coding practices, including parameterized queries and input validation libraries, can prevent this class of vulnerability. Regular security audits and penetration testing should be conducted to identify similar command injection vulnerabilities across the entire application stack, as this pattern often appears in legacy web applications. System administrators should also consider implementing web application firewalls and input filtering mechanisms to detect and block malicious command injection attempts before they can be processed by vulnerable applications.