CVE-2018-10520 in CMS Made Simple
Summary
by MITRE
In CMS Made Simple (CMSMS) through 2.2.7, the "module remove" operation in the admin dashboard contains an arbitrary file deletion vulnerability that can cause DoS, exploitable by an admin user, because the attacker can remove all lib/ files in all directories.
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Analysis
by VulDB Data Team • 02/01/2020
The vulnerability identified as CVE-2018-10520 affects CMS Made Simple versions up to 2.2.7 and represents a critical arbitrary file deletion flaw within the module removal functionality of the administrative dashboard. This vulnerability specifically targets the file deletion mechanisms that occur during module removal operations, creating a path for unauthorized file manipulation that can severely impact system integrity and availability.
The technical flaw stems from insufficient input validation and sanitization within the module removal process, allowing administrative users to manipulate file paths and execute destructive operations against critical system files. When an administrator attempts to remove a module, the system processes the operation without proper verification of file paths, enabling attackers who have administrative access to craft malicious requests that target the lib/ directory structure throughout the CMS installation. This vulnerability operates under CWE-22 which classifies improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks that allow attackers to access files outside the intended directory.
The operational impact of this vulnerability is severe and multifaceted, potentially leading to complete system compromise and denial of service conditions. An attacker with administrative privileges can exploit this vulnerability to delete critical library files, effectively rendering the CMS system inoperable and causing widespread service disruption. The ability to remove all lib/ files across all directories creates a cascading effect that can destroy core functionality, prevent module updates, and compromise the entire content management infrastructure. This vulnerability directly maps to ATT&CK technique T1489 which describes creating or manipulating system processes to deny access to resources, and T1059 which covers command and scripting interpreter usage to execute malicious code.
The exploitation of this vulnerability requires only administrative access, making it particularly dangerous as it leverages legitimate administrative privileges to perform destructive operations. The attack surface is limited to authenticated users with administrative capabilities, but the potential damage is extensive since administrative accounts typically have broad system access and control. Organizations should note that this vulnerability represents a privilege escalation risk where administrative access can be leveraged to cause system-wide damage, making it a critical concern for any CMSMS installation that has administrative accounts with elevated privileges.
Mitigation strategies should focus on immediate patching of the CMSMS platform to version 2.2.8 or later, which contains the necessary fixes for the arbitrary file deletion vulnerability. Additionally, organizations should implement strict administrative access controls, including multi-factor authentication, role-based access restrictions, and regular administrative privilege audits. Network segmentation and monitoring of administrative dashboard activities can help detect suspicious file deletion patterns. The vulnerability also underscores the importance of implementing proper input validation and secure coding practices, particularly for file manipulation operations, which aligns with OWASP Top Ten security controls for preventing insecure direct object references and path traversal attacks. Regular security assessments and penetration testing should include verification of file operation security to prevent similar vulnerabilities from being introduced in future development cycles.