CVE-2002-1821 in Ultimate PHP Board
Summary
by MITRE
Ultimate PHP Board (UPB) 1.0 and 1.0b allows remote authenticated users to gain privileges and perform unauthorized actions via direct requests to (1) admin_members.php, (2) admin_config.php, (3) admin_cat.php, or (4) admin_forum.php.
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability described in CVE-2002-1821 represents a critical access control flaw within the Ultimate PHP Board version 1.0 and 1.0b web application. This issue affects the administrative components of the forum software, specifically targeting four key management files that handle user permissions and system configuration. The vulnerability stems from inadequate authorization checks within these administrative scripts, allowing authenticated users to bypass normal security controls and escalate their privileges to administrative levels.
The technical implementation of this vulnerability exploits the absence of proper access validation mechanisms in the four targeted files. When authenticated users make direct requests to admin_members.php, admin_config.php, admin_cat.php, or admin_forum.php, the application fails to verify whether the requesting user possesses the necessary administrative privileges. This design flaw creates a path for privilege escalation where regular authenticated users can manipulate the application's administrative functions without proper authorization. The vulnerability is particularly dangerous because it operates at the application layer, requiring only valid user credentials to exploit, making it accessible to anyone who can authenticate to the system.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete administrative control over the forum environment. Once exploited, authenticated users can modify user permissions, alter forum configurations, manage categories and forums, and potentially access sensitive data or perform destructive operations. This represents a significant compromise of the application's integrity and confidentiality, as attackers can manipulate the entire forum infrastructure. The vulnerability affects the core security model of the application, undermining the trust model that should protect administrative functions from unauthorized access.
Security professionals should note that this vulnerability aligns with CWE-285, which describes improper authorization issues in software systems. The flaw demonstrates a classic case of insufficient access control validation where the application assumes that authenticated users are authorized to perform all administrative functions. From an attack perspective, this vulnerability maps to several MITRE ATT&CK techniques including privilege escalation and lateral movement, as attackers can leverage the administrative access to explore other system components. Organizations should implement immediate mitigations including proper input validation, role-based access controls, and code reviews to ensure that administrative functions require explicit authorization checks. The vulnerability also highlights the importance of following secure coding practices as outlined in OWASP Top Ten and NIST cybersecurity guidelines, particularly regarding authentication and authorization controls.