CVE-2019-14404 in cPanel
Summary
by MITRE
cPanel before 78.0.18 allows certain file-read operations in the context of the root account via the Exim virtual_user_spam router (SEC-484).
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Analysis
by VulDB Data Team • 07/16/2020
The vulnerability identified as CVE-2019-14404 represents a critical privilege escalation flaw within cPanel software versions prior to 78.0.18. This vulnerability specifically affects the Exim mail server configuration component that handles virtual user spam routing operations. The issue stems from improper access controls within the virtual_user_spam router functionality, which allows unauthorized file read operations to be executed under the root account context. This presents a severe security risk as it enables attackers to potentially access sensitive system files, configuration data, and user information that should remain protected from unauthorized access.
The technical flaw manifests through the Exim virtual_user_spam router implementation where input validation and access control mechanisms fail to properly restrict file system operations. When the router processes certain mail routing scenarios, it inadvertently permits file read operations that bypass normal permission checks. This occurs because the router does not adequately validate or sanitize user-supplied input parameters that influence file system access. The vulnerability specifically leverages the router's handling of virtual user spam filtering configurations to execute unauthorized file reads, potentially exposing critical system information such as password hashes, configuration files, and sensitive data stored in system directories.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to escalate privileges and gain root-level access to affected systems. Attackers can exploit this vulnerability to read system files that contain sensitive information including but not limited to shadow files containing password hashes, SSL certificates, database credentials, and other critical configuration data. The root account context access enables comprehensive system reconnaissance and further exploitation opportunities, potentially leading to complete system compromise. This vulnerability is particularly dangerous in shared hosting environments where cPanel instances are commonly deployed, as it can be leveraged to access multiple user accounts and their associated data.
Organizations affected by this vulnerability should implement immediate mitigations including upgrading to cPanel version 78.0.18 or later, which contains the necessary patches to address the access control issues in the Exim virtual_user_spam router. System administrators should also review and tighten Exim configuration parameters, particularly those related to virtual user spam routing, to minimize potential attack surfaces. The vulnerability aligns with CWE-284 which addresses improper access control, and represents a clear violation of the principle of least privilege. From an attacker perspective, this vulnerability maps to ATT&CK technique T1068 which involves exploiting legitimate credentials and privileges, and T1005 which focuses on data from local system repositories. Security monitoring should be enhanced to detect unusual file read patterns in Exim-related processes, and network segmentation should be implemented to limit potential lateral movement if exploitation occurs. Regular security audits of mail server configurations and access controls are essential to prevent similar vulnerabilities from emerging in other components of the system infrastructure.