CVE-2006-2005 in ClanSys
Summary
by MITRE
Eval injection vulnerability in index.php in ClanSys 1.1 allows remote attackers to execute arbitrary PHP code via PHP code in the page parameter, as demonstrated by using an "include" statement that is injected into the eval statement. NOTE: this issue has been described as file inclusion by some sources, but that is just one attack; the primary vulnerability is eval injection.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/24/2025
The CVE-2006-2005 vulnerability represents a critical eval injection flaw in ClanSys 1.1's index.php script that fundamentally compromises application security through improper input validation and code execution mechanisms. This vulnerability operates at the core of PHP's dynamic execution capabilities, where user-supplied data is directly incorporated into eval statements without adequate sanitization or validation processes. The flaw specifically manifests when the page parameter is manipulated to contain PHP code that gets executed within the eval context, creating a pathway for remote attackers to inject malicious payloads and execute arbitrary commands on the target system.
The technical implementation of this vulnerability stems from the application's failure to properly sanitize user input before incorporating it into dynamic PHP execution contexts. When attackers submit PHP code through the page parameter, the system's code processing logic fails to distinguish between legitimate application data and malicious code fragments. This allows attackers to craft payloads that include include statements or other PHP functions that get executed within the eval context, effectively bypassing normal security boundaries and executing arbitrary PHP code on the server. The vulnerability operates under CWE-94, which specifically addresses "Improper Control of Generation of Code ('Code Injection')" and falls within the broader category of code injection attacks that have been systematically catalogued in the CWE database since 2004.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete control over the affected server environment. Once exploited, attackers can perform file operations, execute system commands, access sensitive data, and potentially escalate privileges within the application's security context. The remote nature of the attack means that exploitation can occur from any location without requiring physical access to the system, making it particularly dangerous for web applications that are publicly accessible. The vulnerability's classification as eval injection rather than simple file inclusion indicates that the attack vector is more sophisticated and dangerous, as eval injection can execute any valid PHP code rather than being limited to file inclusion attacks. This makes the vulnerability particularly attractive to attackers who can leverage it for complete system compromise and persistent access.
Mitigation strategies for this vulnerability must address both the immediate code execution risk and the underlying architectural flaws that allowed the injection to occur. The primary recommendation involves implementing comprehensive input validation and sanitization mechanisms that prevent user-supplied data from being directly incorporated into eval statements. Applications should employ parameterized queries, input filtering, and proper escaping mechanisms to ensure that any user-supplied content cannot be interpreted as executable code. Additionally, implementing proper access controls, input whitelisting, and strict validation of all parameters can significantly reduce the attack surface. Organizations should also consider implementing web application firewalls and runtime monitoring systems that can detect and block suspicious code execution patterns. The remediation process should include thorough code review and security testing to identify similar injection vulnerabilities throughout the application's codebase, as this type of flaw often indicates broader security architecture issues that may affect other components. The vulnerability's characteristics align with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PHP" and T1566.001 for "Phishing: Spearphishing Attachment", making it particularly relevant for security teams implementing defensive strategies against these attack vectors.