CVE-2017-18430 in cPanel
Summary
by MITRE
In cPanel before 66.0.2, user and group ownership may be incorrectly set when using reassign_post_terminate_cruft (SEC-294).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2017-18430 affects cPanel versions prior to 66.0.2 and relates to improper handling of file ownership during post-termination processes. This issue specifically impacts the reassign_post_terminate_cruft functionality which is designed to manage file permissions and ownership after certain system operations. The flaw represents a significant security concern as it allows for incorrect user and group ownership assignments that can persist beyond the intended scope of the operation.
The technical implementation of this vulnerability stems from inadequate validation and processing of ownership information within the cPanel administrative interface. When the reassign_post_terminate_cruft function executes, it fails to properly verify or enforce the correct user and group identifiers for files and directories. This misconfiguration can result in files being assigned to incorrect ownership contexts, potentially allowing unauthorized users to gain elevated privileges or access to resources they should not legitimately possess. The vulnerability operates at the filesystem level and impacts the core privilege management mechanisms that cPanel employs to maintain security boundaries between user accounts.
From an operational perspective, this vulnerability creates a persistent security risk that can be exploited by malicious actors with access to compromised accounts or through privilege escalation techniques. The incorrect ownership assignments can lead to unauthorized file access, data exposure, and potential system compromise. Security researchers have identified this issue as particularly dangerous because it can persist across multiple system operations and may not be immediately apparent to administrators. The vulnerability can be leveraged to maintain persistent access to system resources or to escalate privileges within the cPanel environment, making it a critical concern for organizations relying on cPanel for hosting services.
Organizations should prioritize immediate patching of affected cPanel installations to version 66.0.2 or later, which contains the necessary fixes for the ownership assignment logic. System administrators should conduct comprehensive audits of file ownership and permissions following patch deployment to ensure no lingering effects from the vulnerability. Additional mitigations include implementing strict access controls, monitoring for unusual file ownership changes, and maintaining regular security assessments of hosting environments. This vulnerability aligns with CWE-276, which addresses improper file permissions, and can be mapped to ATT&CK technique T1068, privilege escalation through improper file permissions, highlighting the broader security implications beyond the immediate technical flaw.