CVE-2006-5138 in UBB.threads
Summary
by MITRE
Groupee UBB.threads 6.5.1.1 allows remote attackers to obtain sensitive information via a direct request for cron/php/subscriptions.php, which reveals the path in an error message.
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Analysis
by VulDB Data Team • 04/23/2026
The vulnerability identified as CVE-2006-5138 affects Groupee UBB.threads version 6.5.1.1, representing a sensitive information disclosure weakness that exposes system paths through improper error handling mechanisms. This flaw resides within the forum software's subscription management functionality, specifically in the cron/php/subscriptions.php script which is designed to handle automated subscription-related tasks. The vulnerability demonstrates a classic path disclosure issue where the application fails to properly sanitize error messages before displaying them to remote attackers, thereby revealing critical system path information that could be leveraged for further exploitation attempts.
The technical implementation of this vulnerability stems from the application's failure to implement proper input validation and error handling procedures within the subscriptions.php script. When a remote attacker makes a direct request to this specific endpoint, the system generates an error message that inadvertently includes the full server path where the application is installed. This occurs because the script does not properly validate or sanitize the request parameters before processing them, allowing the underlying system to expose directory structures through error output mechanisms. The flaw aligns with CWE-209, which specifically addresses the exposure of error messages containing sensitive information, and represents a fundamental security misconfiguration that violates secure coding practices.
The operational impact of this vulnerability extends beyond simple information disclosure, as the revealed system paths provide attackers with crucial reconnaissance data that can facilitate more sophisticated attacks. An attacker who successfully exploits this vulnerability gains knowledge of the server's file system structure, which can be used to map the application's directory hierarchy, identify potential weak points in the file system permissions, and plan subsequent exploitation attempts. This information disclosure can be particularly damaging when combined with other vulnerabilities, as it provides attackers with precise locations of configuration files, database connection details, or other sensitive components that might be stored in predictable locations within the disclosed paths. The vulnerability also aligns with ATT&CK technique T1083, which covers the discovery of file and directory permissions, and T1068, which addresses privilege escalation through system information gathering.
Mitigation strategies for this vulnerability should focus on implementing proper error handling mechanisms that prevent sensitive information from being exposed to end users or attackers. The primary recommendation involves modifying the subscriptions.php script to sanitize all error messages and ensure that system paths are not included in the output regardless of the error condition. Organizations should implement comprehensive input validation for all script parameters and establish secure error handling procedures that log errors internally without exposing them to external users. Additionally, the application should be updated to a patched version that addresses this specific information disclosure issue, as the vulnerability represents a known weakness in the software's security architecture. System administrators should also consider implementing web application firewalls that can detect and block direct requests to administrative or cron scripts, thereby reducing the attack surface available to potential adversaries. Regular security assessments and code reviews should be conducted to identify similar path disclosure vulnerabilities in other components of the application stack, ensuring that the software maintains robust security posture against information leakage attacks.