CVE-2004-2044 in PHP-Nuke
Summary
by MITRE
PHP-Nuke 7.3, and other products that use the PHP-Nuke codebase such as the Nuke Cops betaNC PHP-Nuke Bundle, OSCNukeLite 3.1, and OSC2Nuke 7x do not properly use the eregi() PHP function with $_SERVER[ PHP_SELF ] to identify the calling script, which allows remote attackers to directly access scripts, obtain path information via a PHP error message, and possibly gain access, as demonstrated using an HTTP request that contains the "admin.php" string.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability identified as CVE-2004-2044 represents a critical security flaw within PHP-Nuke 7.3 and its derivative products that stems from improper handling of the eregi() function when processing the $_SERVER[PHP_SELF] variable. This weakness creates a pathway for remote attackers to bypass normal access controls and directly execute administrative functions within the affected applications. The vulnerability specifically exploits how these systems identify the calling script through regular expression matching, which fails to properly validate or sanitize input from the PHP_SELF server variable. The flaw manifests when attackers craft HTTP requests containing the string "admin.php" which can then be processed by the vulnerable code to directly access administrative scripts without proper authentication or authorization checks.
The technical implementation of this vulnerability resides in the insecure use of the eregi() function, which is a deprecated regular expression matching function in PHP that lacks proper input validation mechanisms. When the affected systems process $_SERVER[PHP_SELF] through this function, they fail to properly sanitize or validate the input, allowing malicious actors to inject arbitrary strings that can manipulate the script execution flow. This particular implementation pattern creates a path traversal scenario where attackers can directly access administrative functions by leveraging the predictable nature of how these applications handle the PHP_SELF variable. The vulnerability operates at the application layer and can be exploited through HTTP requests that manipulate the server variable to point to administrative scripts within the application's file structure.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential information disclosure and privilege escalation capabilities. Attackers can exploit this flaw to obtain sensitive path information through PHP error messages that reveal internal file structures and directory layouts. This information disclosure aspect is particularly dangerous as it provides attackers with detailed knowledge of the application's internal architecture, potentially enabling more sophisticated attacks. The vulnerability can lead to complete system compromise when combined with other exploitation techniques, as attackers gain access to administrative functions that control user management, database operations, content modification, and system configuration settings. The widespread adoption of PHP-Nuke and its derivatives means that numerous web applications across different organizations could be vulnerable to this attack vector.
Mitigation strategies for CVE-2004-2044 must address both the immediate code-level vulnerability and broader security architecture considerations. The primary remediation involves replacing the vulnerable eregi() function with secure alternatives such as preg_match() or stristr() functions that properly validate input before processing. Organizations should implement proper input sanitization techniques that validate and filter all data derived from server variables including PHP_SELF, ensuring that only legitimate script names are processed. This vulnerability aligns with CWE-20 Improper Input Validation, where inadequate validation of input data leads to security flaws in applications. The attack pattern demonstrates characteristics consistent with ATT&CK technique T1068, which involves the use of legitimate credentials or system privileges to gain unauthorized access to systems. Additionally, organizations should implement proper access controls and authentication mechanisms that do not rely solely on script name validation, establishing robust authorization frameworks that verify user permissions before granting access to administrative functions. Regular security audits and code reviews should focus on identifying similar patterns of insecure input handling, particularly within legacy PHP applications that may contain other vulnerable functions. The remediation process should also include updating to supported versions of PHP-Nuke and its derivatives, as newer versions typically contain improved security measures and proper input validation routines that prevent this class of vulnerability from occurring.