CVE-2005-0614 in phpBB
Summary
by MITRE
sessions.php in phpBB 2.0.12 and earlier allows remote attackers to gain administrator privileges via the autologinid value in a cookie.
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Analysis
by VulDB Data Team • 09/25/2025
The vulnerability described in CVE-2005-0614 represents a critical authentication bypass flaw within the phpBB bulletin board system version 2.0.12 and earlier. This security weakness resides in the sessions.php file which handles user session management and authentication processes. The flaw specifically targets the autologinid cookie parameter that is used to maintain user sessions and automatically log users back into the system. Attackers can exploit this vulnerability by manipulating the autologinid value contained within the cookie, potentially allowing them to escalate privileges from regular user status to administrator level access.
The technical implementation of this vulnerability stems from inadequate input validation and improper session handling within the phpBB application. When users access the forum, the system generates a session cookie containing an autologinid value that should be securely validated against the database to confirm user identity and permissions. However, the flawed code fails to properly validate this autologinid parameter, allowing attackers to craft malicious cookie values that bypass normal authentication checks. This weakness operates at the intersection of multiple security principles including authentication integrity and session management, making it particularly dangerous for web applications that rely on cookie-based authentication mechanisms.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete administrative control over the affected phpBB installation. Once an attacker successfully exploits this flaw, they gain the ability to modify forum settings, delete or alter user accounts, post malicious content, and potentially use the compromised system as a launching point for further attacks against other systems within the network. The vulnerability affects all versions up to and including phpBB 2.0.12, representing a significant risk for organizations that have not updated their installations. This type of privilege escalation vulnerability aligns with CWE-287, which addresses improper authentication issues, and can be categorized under ATT&CK technique T1078 for valid accounts, as attackers can leverage the compromised administrative session to maintain persistent access.
Security professionals should immediately implement mitigation strategies including updating to phpBB version 2.0.13 or later, which contains the necessary patches to address this vulnerability. Additionally, organizations should review their cookie security configurations, implement proper input validation for all cookie parameters, and consider additional security measures such as secure cookie flags, HttpOnly attributes, and regular security audits. The vulnerability demonstrates the critical importance of proper session management and input validation in web applications, serving as a reminder that even minor flaws in authentication systems can result in complete system compromise. Organizations should also consider implementing web application firewalls and monitoring for suspicious cookie manipulation patterns to detect potential exploitation attempts.