CVE-2016-9418 in MyBB
Summary
by MITRE
MyBB (aka MyBulletinBoard) before 1.8.8 on Windows and MyBB Merge System before 1.8.8 on Windows might allow remote attackers to obtain sensitive information from ACP backups via vectors involving a short name.
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Analysis
by VulDB Data Team • 08/08/2020
The vulnerability identified as CVE-2016-9418 affects MyBB bulletin board systems and MyBB Merge System versions prior to 1.8.8 on Windows platforms. This security flaw resides in the backup functionality of the Administrative Control Panel where sensitive information could be exposed to remote attackers. The vulnerability specifically manifests when backup files are created with short filenames, creating an exploitable condition that allows unauthorized access to potentially sensitive data.
The technical implementation of this vulnerability stems from improper handling of backup file naming conventions within the Windows environment. When the system generates backup files, it creates short filenames that may not properly obscure the underlying file structure or contain sensitive information. Attackers can exploit this by crafting specific requests that target these short filename backups, potentially gaining access to administrative backup files that contain database credentials, user information, or other confidential data. This represents a classic case of information exposure through improper file handling and naming conventions.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with potential access to administrative backup files that may contain database connection strings, user credentials, or other sensitive configuration data. In a production environment, this could lead to complete system compromise if attackers can leverage the exposed information to escalate privileges or gain deeper access to the underlying infrastructure. The vulnerability particularly affects Windows deployments where short filename generation is more prevalent and can be exploited more effectively than in other operating system environments.
Security professionals should note that this vulnerability aligns with CWE-200, which addresses information exposure, and represents a weakness in backup and restore functionality. The attack vector typically involves remote exploitation through web-based interfaces, making it particularly dangerous in publicly accessible systems. Organizations should implement immediate mitigations including updating to MyBB version 1.8.8 or later, which addresses the short filename handling issue, and reviewing backup file permissions to ensure they are not accessible to unauthorized users. Additionally, implementing proper access controls and monitoring for unusual backup file access patterns can help detect potential exploitation attempts.
The broader implications of this vulnerability highlight the importance of proper file handling and naming conventions in web applications, particularly those dealing with sensitive data and administrative functions. System administrators should conduct thorough reviews of backup and restore mechanisms across all web applications, ensuring that sensitive information is properly protected regardless of the operating system environment. This vulnerability also emphasizes the need for regular security updates and patch management processes, as the affected versions were released before the vulnerability was properly addressed in the software updates. Organizations should also consider implementing network segmentation and additional monitoring controls to detect and prevent unauthorized access attempts to backup systems.