CVE-2006-3994 in XMB
Summary
by MITRE
SQL injection vulnerability in the u2u_send_recp function in u2u.inc.php in XMB (aka extreme message board) 1.9.6 Alpha and earlier allows remote attackers to execute arbitrary SQL commands via the u2uid parameter to u2u.php, which is directly accessed from $_POST and bypasses the protection scheme.
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Analysis
by VulDB Data Team • 07/11/2024
The vulnerability identified as CVE-2006-3994 represents a critical SQL injection flaw within the XMB (extreme message board) forum software version 1.9.6 Alpha and earlier. This vulnerability resides in the u2u_send_recp function located in the u2u.inc.php file, which processes user-to-user messaging functionality. The flaw occurs when the u2u.php script directly accesses the u2uid parameter from the $_POST superglobal array without proper input sanitization or validation, creating an exploitable entry point for malicious actors.
The technical implementation of this vulnerability stems from inadequate parameter handling within the message board's user communication system. When users send private messages through the platform, the u2uid parameter containing user identifiers is passed directly into SQL query construction without appropriate escaping or parameterization. This design flaw allows attackers to inject malicious SQL code through the u2uid parameter, effectively bypassing all existing protection mechanisms. The vulnerability operates at the application layer and can be exploited remotely without requiring authentication, making it particularly dangerous for publicly accessible forum installations.
The operational impact of this vulnerability is severe and multifaceted. Attackers can execute arbitrary SQL commands against the underlying database, potentially leading to complete database compromise, data exfiltration, user credential theft, and unauthorized modifications to forum content. The vulnerability affects the entire user management and messaging system, enabling attackers to escalate privileges, create administrative accounts, or even gain shell access to the server if the database is configured with appropriate permissions. This type of vulnerability directly violates the principle of least privilege and represents a fundamental failure in input validation and secure coding practices.
Security professionals should note this vulnerability aligns with CWE-89, which specifically addresses SQL injection weaknesses in software applications. The flaw also maps to several ATT&CK techniques including T1190 (Exploit Public-Facing Application) and T1071.004 (Application Layer Protocol: DNS) when attackers use the vulnerability to establish persistent access. Organizations should immediately implement mitigations including input validation, parameterized queries, and proper access controls. The most effective immediate fix involves sanitizing all user inputs, particularly those derived from $_POST variables, and implementing proper SQL query parameterization. Additionally, network segmentation and intrusion detection systems should be deployed to monitor for exploitation attempts, while regular security audits should verify that similar vulnerabilities do not exist in other components of the messaging infrastructure.