CVE-2018-20941 in cPanel
Summary
by MITRE
cPanel before 68.0.27 allows arbitrary file-read operations via restore adminbin (SEC-349).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2018-20941 represents a critical arbitrary file read flaw within cPanel software versions prior to 68.0.27. This security weakness stems from inadequate input validation and access control mechanisms within the restore adminbin functionality, which is part of cPanel's administrative tools designed for system restoration and configuration management. The flaw specifically affects the administrative interface component that handles binary file restoration operations, creating a pathway for unauthorized file access that could potentially expose sensitive system information.
The technical implementation of this vulnerability occurs through the restore adminbin module's insufficient sanitization of user-supplied parameters during file restoration processes. Attackers can exploit this weakness by crafting malicious requests that bypass normal access controls and traverse the file system to read arbitrary files on the server. The vulnerability operates at the application level where proper authentication and authorization checks fail to validate the legitimacy of file access requests, allowing attackers to specify file paths that should otherwise be restricted. This type of flaw aligns with CWE-22 Path Traversal and CWE-285 Improper Authorization categories, demonstrating how inadequate input validation combined with weak access controls creates exploitable conditions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the ability to access sensitive configuration files, database credentials, system logs, and potentially other critical administrative resources. The restored binary functionality in cPanel typically handles system-level operations and may contain references to internal paths, configuration parameters, or authentication tokens that could be leveraged for further compromise. Organizations using affected cPanel versions face significant risk of unauthorized access to their hosting environments, potentially leading to complete system compromise, data exfiltration, or service disruption.
Security professionals should prioritize immediate remediation through cPanel version 68.0.27 or later, which includes proper input validation and access control measures for the restore adminbin functionality. Additional mitigations include implementing network-level restrictions to limit administrative access, deploying web application firewalls to monitor for suspicious file access patterns, and conducting thorough security assessments of administrative interfaces. The vulnerability demonstrates the importance of proper access control implementation and input validation in administrative tools, aligning with ATT&CK techniques related to privilege escalation and credential access. Organizations should also review their overall administrative access policies and implement principle of least privilege controls to minimize the impact of similar vulnerabilities in other system components.