CVE-2008-5576 in sCssBoard
Summary
by MITRE
admin/forums.php in sCssBoard 1.0, 1.1, 1.11, and 1.12 allows remote attackers to bypass authentication and gain administrative access via a large value of the current_user[users_level] parameter.
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Analysis
by VulDB Data Team • 10/17/2024
The vulnerability identified as CVE-2008-5576 represents a critical authentication bypass flaw within the sCssBoard bulletin board software versions 1.0 through 1.12. This issue resides in the admin/forums.php file where improper input validation allows malicious actors to manipulate the current_user[users_level] parameter to escalate their privileges. The vulnerability stems from a lack of proper parameter sanitization and validation mechanisms that should have prevented arbitrary value injection into the administrative access control system. Such flaws typically fall under CWE-285 which addresses improper authorization in software systems, specifically targeting the weakness where applications fail to properly validate user permissions and roles.
The technical exploitation of this vulnerability occurs when remote attackers submit a crafted HTTP request containing an excessively large value for the current_user[users_level] parameter. This parameter normally controls user access levels within the application's permission model, with higher numeric values typically representing administrative privileges. By injecting a large numeric value, attackers can bypass the normal authentication checks that would normally validate whether a user possesses sufficient privileges to access administrative functions. The flaw essentially allows attackers to impersonate administrators without proper credentials, effectively providing them with complete control over the forum's administrative interface and potentially the underlying system if no additional security measures are in place.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to perform a wide range of malicious activities within the compromised system. Administrators can modify forum settings, delete or alter user accounts, post malicious content, and potentially access sensitive data stored within the forum database. The vulnerability also creates opportunities for attackers to establish persistent access through the administrative interface, making it particularly dangerous for systems that rely on sCssBoard for community management or business operations. This type of authentication bypass vulnerability aligns with ATT&CK technique T1078 which covers legitimate credentials usage, as attackers can leverage the administrative privileges to maintain access without detection.
Mitigation strategies for this vulnerability require immediate implementation of input validation and parameter sanitization measures within the affected application. The most effective approach involves implementing strict type checking and range validation for the users_level parameter, ensuring that only legitimate administrative values are accepted. Additionally, implementing proper session management and access control checks at multiple points within the application can help prevent privilege escalation even if individual validation points fail. Security patches should be applied immediately to upgrade to versions that address this specific authentication bypass flaw, as the vulnerability affects multiple versions of the software and represents a fundamental weakness in the application's security architecture. Organizations should also conduct thorough security assessments of their web applications to identify similar input validation vulnerabilities that could allow similar privilege escalation attacks.