CVE-2004-0621 in Newsletter ZWS
Summary
by MITRE
admin.php in Newsletter ZWS allows remote attackers to gain administrative privileges via a list_user operation with the ulevel parameter set to 1 (administrator level), which lists all users and their passwords.
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Analysis
by VulDB Data Team • 06/30/2025
The vulnerability described in CVE-2004-0621 represents a critical access control flaw in the Newsletter ZWS web application that enables remote attackers to escalate their privileges and gain full administrative control over the system. This vulnerability exists within the admin.php file and specifically targets the list_user operation functionality, where an improperly validated ulevel parameter allows unauthorized users to manipulate their privilege level to administrator status. The flaw stems from inadequate input validation and authentication checks that fail to properly verify user permissions before executing administrative operations.
The technical implementation of this vulnerability demonstrates a classic case of insufficient privilege checking and parameter manipulation. When an attacker submits a request to the list_user operation with ulevel parameter set to 1, the application fails to authenticate whether the requesting user actually possesses administrative privileges before granting access to the user listing functionality. This creates a privilege escalation path where any authenticated user can essentially impersonate an administrator and gain access to sensitive user information including password hashes or plaintext credentials. The vulnerability operates at the application layer and leverages the principle of least privilege violation, where users are granted more access than they should legitimately possess.
From an operational perspective, this vulnerability poses severe security implications for organizations using the Newsletter ZWS application. The ability to list all users and their passwords effectively compromises the entire user base and provides attackers with a comprehensive map of system users. This information can be exploited for further attacks including credential reuse, account takeover, and insider threat exploitation. The vulnerability is particularly dangerous because it allows remote exploitation without requiring any special tools or local access, making it highly attractive to attackers. The impact extends beyond simple privilege escalation as it provides a foundation for more sophisticated attacks and can lead to complete system compromise.
The vulnerability aligns with CWE-285, which addresses improper authorization in software systems, and represents a clear violation of the principle of least privilege. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and credential access phases, specifically T1078 for valid accounts and T1566 for credential harvesting. The flaw also demonstrates characteristics of T1210, which involves exploitation of remote services through credential manipulation. Organizations should implement immediate mitigations including input validation, authentication checks, and privilege verification mechanisms to address this vulnerability. The recommended remediation involves enforcing proper access controls, implementing robust parameter validation, and ensuring that administrative operations require proper authentication tokens or session verification before executing privileged functions. Additionally, regular security audits and code reviews should be conducted to identify similar privilege escalation vulnerabilities in other applications and prevent future occurrences of such security flaws.