CVE-2018-10521 in CMS Made Simple
Summary
by MITRE
In CMS Made Simple (CMSMS) through 2.2.7, the "file move" operation in the admin dashboard contains an arbitrary file movement vulnerability that can cause DoS, exploitable by an admin user, because config.php can be moved into an incorrect directory.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/01/2020
The vulnerability identified as CVE-2018-10521 affects CMS Made Simple versions up to and including 2.2.7, representing a critical security flaw in the administrative dashboard functionality. This issue stems from insufficient input validation and access control mechanisms within the file management system, specifically during the file move operation. The vulnerability allows an authenticated administrative user to manipulate file paths in a manner that could lead to system disruption and potential unauthorized access to sensitive configuration files. The flaw exists within the core file management subsystem that handles user interactions with the content management system's file structure through the web-based administrative interface.
The technical implementation of this vulnerability resides in the improper handling of file movement operations within the CMSMS administrative environment. When an administrator attempts to move files using the dashboard interface, the system fails to properly validate the destination directory paths, allowing malicious file movement operations that can place critical system files in inappropriate locations. Specifically, the config.php file which contains essential system configuration data and database credentials can be moved to directories where it becomes inaccessible or executable, potentially leading to system instability or complete service disruption. This vulnerability operates under CWE-22 which classifies it as Path Traversal, specifically involving improper restriction of operations within a restricted file access environment. The flaw demonstrates a lack of proper input sanitization and path validation that enables an attacker with administrative privileges to manipulate the file system structure in ways that were not intended by the application's design.
The operational impact of CVE-2018-10521 extends beyond simple denial of service conditions to potentially compromise the entire CMSMS installation. An attacker with administrative access can exploit this vulnerability to move the config.php file into directories where it cannot be properly accessed by the web server, effectively rendering the CMSMS installation non-functional or causing it to behave unpredictably. The vulnerability creates a condition where the system's configuration becomes inaccessible, leading to cascading failures in the application's ability to function properly. This can result in complete system outages, data unavailability, and potential information disclosure if the configuration file contains sensitive database connection details or cryptographic keys. The attack vector is particularly concerning because it requires only administrative privileges, which are typically limited to trusted users but represent a significant attack surface when compromised. This vulnerability aligns with ATT&CK technique T1059 which involves executing malicious code through legitimate system processes, and T1489 which involves denying access to resources through system disruption.
Mitigation strategies for CVE-2018-10521 should focus on both immediate remediation and long-term security hardening measures. The most effective immediate solution involves upgrading to CMS Made Simple version 2.2.8 or later, where the vulnerability has been addressed through proper input validation and path restriction mechanisms. Organizations should also implement strict access control measures ensuring that administrative privileges are granted only to trusted individuals and that regular security audits are conducted to verify proper file system permissions. The implementation of proper input validation and sanitization should be enforced throughout the application's file management operations to prevent similar path traversal vulnerabilities. Additionally, organizations should consider implementing web application firewalls and intrusion detection systems that can monitor for suspicious file movement patterns and alert security teams to potential exploitation attempts. Regular backup procedures should be maintained to ensure rapid recovery in case of successful exploitation, and security monitoring should include real-time tracking of administrative user activities to detect anomalous file movement operations that may indicate exploitation attempts. The vulnerability highlights the importance of proper privilege separation and the need for comprehensive security testing of all administrative functions within content management systems.