CVE-2017-18427 in cPanel
Summary
by MITRE
In cPanel before 66.0.2, weak log-file permissions can occur after account modification (SEC-289).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2017-18427 affects cPanel versions prior to 66.0.2 and relates to improper log file permission handling during account modification processes. This issue represents a significant security weakness that can compromise system integrity and confidentiality. The vulnerability falls under the category of improper permission management and can be classified as a CWE-732: Incorrect Permission Assignment for Critical Resource, which directly impacts the principle of least privilege in system security. When cPanel handles account modifications, it fails to properly set restrictive permissions on log files that are created or updated during these operations, potentially exposing sensitive system information to unauthorized users.
The technical flaw manifests when cPanel executes account modification routines that generate or update log files without ensuring appropriate file permissions are applied. This typically occurs during user account creation, modification, or deletion processes where log entries are written to disk. The weak permissions can allow local users or even remote attackers with limited access to read sensitive information contained within these log files. The vulnerability is particularly concerning because cPanel log files often contain detailed information about system operations, user activities, and potentially sensitive configuration data that could be leveraged for further exploitation. The issue demonstrates a failure in privilege separation and access control enforcement within the cPanel application framework, creating opportunities for information disclosure attacks.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. Attackers who can read these improperly permissioned log files may gain insights into system configurations, user activities, and operational patterns that could be used for privilege escalation or targeted attacks against other system components. This vulnerability can be particularly damaging in shared hosting environments where multiple users operate under a single cPanel instance, as it may allow one user to access another user's log information. The exposure of log file contents can reveal authentication attempts, system errors, and potentially sensitive data that should remain protected. According to ATT&CK framework, this vulnerability maps to T1070.002: Indicator Removal on Host, as compromised log files may contain evidence of malicious activity that could be obscured by weak permissions, and T1083: File and Directory Discovery, as attackers can more easily locate and access sensitive system files.
Mitigation strategies for CVE-2017-18427 primarily involve upgrading to cPanel version 66.0.2 or later, which includes the necessary permission handling fixes. System administrators should also implement proactive monitoring of log file permissions to ensure that newly created or modified log files maintain appropriate access controls. Regular security audits of file permissions, particularly in critical system directories, can help identify and remediate similar issues before they can be exploited. The implementation of automated permission checking tools and regular vulnerability assessments can provide additional layers of protection. Organizations should also consider implementing principle of least privilege controls, ensuring that log files are only accessible to authorized system processes and users with legitimate operational needs. Additionally, the use of centralized logging solutions with proper access controls can reduce the risk associated with local log file exposure, as these systems typically enforce more robust permission models and provide better audit trails for security monitoring activities.