CVE-2016-10830 in cPanel
Summary
by MITRE
cPanel before 55.9999.141 allows ACL bypass for AppConfig applications via magic_revision (SEC-100).
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Analysis
by VulDB Data Team • 11/20/2023
The vulnerability identified as CVE-2016-10830 represents a critical access control flaw within cPanel software versions prior to 55.9999.141. This issue specifically affects the AppConfig application framework component of cPanel, which is designed to manage and configure various application settings. The vulnerability stems from improper validation of the magic_revision parameter, which is used to track configuration changes and maintain application state. When this parameter is manipulated by an unauthorized user, it can bypass the intended access control lists that should restrict who can modify application configurations. The flaw essentially allows attackers to escalate their privileges and gain unauthorized access to application configuration data that should be protected by the ACL system. This vulnerability directly impacts the principle of least privilege and can lead to unauthorized modification of critical application settings.
The technical implementation of this vulnerability occurs within the AppConfig application's handling of the magic_revision parameter, which is typically used to ensure that configuration changes are properly tracked and validated. In vulnerable versions, the system fails to properly authenticate or authorize requests that modify this parameter, allowing attackers to craft malicious requests that appear to originate from legitimate users with appropriate privileges. This bypass mechanism operates at the application layer and can be exploited through various attack vectors including web interface manipulation, API calls, or direct parameter injection. The vulnerability is particularly concerning because it leverages the existing trust mechanisms within the application framework, making detection more challenging. According to CWE classification, this represents a weakness in access control where insufficient validation of parameters leads to privilege escalation. The flaw aligns with ATT&CK technique T1078 which covers valid accounts and T1496 which covers Resource Hijacking, as unauthorized users can gain access to resources they should not be able to modify.
The operational impact of CVE-2016-10830 extends beyond simple privilege escalation to potentially compromise entire application configurations and associated data. An attacker who successfully exploits this vulnerability could modify critical application settings, inject malicious code, or alter security configurations that protect the application environment. This could result in complete application compromise, data exposure, or serve as a stepping stone for further attacks within the system. Organizations using vulnerable cPanel versions face significant risk of unauthorized configuration changes that could affect multiple applications running on the same platform. The vulnerability is particularly dangerous in shared hosting environments where multiple customers share the same cPanel instance, as it could allow one user to affect others' application configurations. The impact is amplified when considering that AppConfig applications often handle sensitive data and configuration parameters that control application behavior, making this vulnerability a critical concern for system administrators and security teams responsible for maintaining application integrity and security.
Mitigation strategies for CVE-2016-10830 should prioritize immediate software updates to cPanel version 55.9999.141 or later, which contains the necessary patches to address the ACL bypass vulnerability. System administrators should also implement additional monitoring and logging of configuration change activities, particularly around the magic_revision parameter usage. Network segmentation and access controls should be reviewed to limit exposure of cPanel interfaces to untrusted networks. Security teams should conduct thorough vulnerability assessments to identify any potential exploitation attempts that may have occurred prior to patching. Additional defensive measures include implementing web application firewalls that can detect and block suspicious parameter manipulation attempts, and establishing more robust audit trails for application configuration changes. Organizations should also consider implementing automated patch management processes to ensure timely deployment of security updates and maintain updated inventories of all cPanel components and their versions to prevent similar vulnerabilities from remaining undetected. The remediation process should include verification that all AppConfig applications are properly configured with appropriate access controls and that the patched version maintains expected functionality without introducing regressions.