CVE-2017-18413 in cPanel
Summary
by MITRE
In cPanel before 67.9999.103, the backup system overwrites root's home directory when a mount disappears (SEC-299).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2017-18413 affects cPanel versions prior to 67.9999.103 and resides within the backup system's handling of filesystem operations. This issue manifests when a mounted filesystem becomes unavailable or disappears during backup operations, creating a critical security flaw that could lead to unauthorized system compromise. The vulnerability specifically targets the root user's home directory, making it particularly dangerous for system administrators who rely on cPanel for server management. The backup system's improper error handling during mount disconnection events creates a window of opportunity for malicious actors to exploit the system's behavior.
The technical flaw stems from inadequate validation and error handling within cPanel's backup module when encountering unexpected filesystem disconnections. When a mount point becomes inaccessible, the system fails to properly validate the backup destination before proceeding with operations that could overwrite critical system directories. This behavior violates fundamental security principles and creates a path for privilege escalation attacks. The vulnerability can be categorized under CWE-284 Access Control Issues, specifically relating to improper privilege management during system operations. The flaw represents a classic case of insufficient input validation and error handling that allows arbitrary file system modifications when system conditions deviate from expected behavior.
The operational impact of this vulnerability extends beyond simple data overwrite scenarios and creates significant risks for system integrity and availability. Attackers could potentially leverage this vulnerability to gain root access, modify system binaries, or establish persistent backdoors within the compromised cPanel environment. The vulnerability affects systems where cPanel manages backups to mounted filesystems, which is common in enterprise environments and shared hosting platforms. Organizations running affected versions face potential data loss, system compromise, and unauthorized access to sensitive server resources. The impact is particularly severe for hosting providers who manage multiple client accounts, as a single compromised backup operation could affect numerous systems simultaneously.
Mitigation strategies for CVE-2017-18413 should prioritize immediate patching of cPanel installations to version 67.9999.103 or later, which contains the necessary fixes for proper mount handling during backup operations. System administrators should implement additional monitoring for filesystem mount status and backup operations to detect anomalous behavior. Network segmentation and access controls should be strengthened to limit potential attack vectors, particularly focusing on backup system interfaces. The vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter and T1078 Valid Accounts, as attackers could potentially exploit this flaw to establish persistent access through compromised backup operations. Organizations should also implement regular security audits of backup systems and ensure proper file system permissions are maintained to prevent unauthorized modifications during backup processes.