CVE-2017-18465 in cPanel
Summary
by MITRE
cPanel before 62.0.17 does not have a sufficient list of reserved usernames (SEC-227).
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2017-18465 affects cPanel versions prior to 62.0.17 and stems from an insufficient list of reserved usernames within the control panel's user management system. This weakness represents a significant security flaw that allows unauthorized users to potentially create accounts with names that should be restricted for system integrity and security purposes. The issue specifically relates to the lack of comprehensive validation for username creation, which can lead to conflicts with system-critical accounts or administrative functions.
From a technical perspective, the flaw manifests when cPanel fails to properly validate user input against a complete set of reserved usernames that are typically required for system operations. This includes accounts such as root, admin, administrator, and other system-critical identifiers that should be protected from user creation. The vulnerability allows attackers to register accounts with these reserved names, potentially enabling privilege escalation or system compromise. This weakness aligns with CWE-639, which addresses authorization flaws in user account management systems. The incomplete validation process creates a vector for attackers to bypass normal access controls and potentially gain elevated privileges within the system.
The operational impact of this vulnerability extends beyond simple account creation conflicts. When attackers can register accounts with reserved usernames, they may be able to impersonate system administrators or exploit system accounts for malicious purposes. This can result in unauthorized access to sensitive system functions, data breaches, or complete system compromise. The vulnerability particularly affects environments where cPanel serves as the primary interface for system administration, making it a critical concern for hosting providers and system administrators managing multiple user accounts. Organizations using older cPanel versions face increased risk of unauthorized access and potential lateral movement within their network infrastructure.
Mitigation strategies for CVE-2017-18465 primarily involve upgrading to cPanel version 62.0.17 or later, which includes the corrected reserved username validation. System administrators should also implement additional monitoring mechanisms to detect unusual account creation patterns and regularly audit user accounts for potential conflicts with reserved names. Network segmentation and access control measures can help limit the impact if an attacker successfully exploits this vulnerability. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates. The remediation process should include comprehensive testing to verify that the updated validation logic properly prevents creation of accounts with reserved usernames, aligning with best practices outlined in the MITRE ATT&CK framework for credential access and privilege escalation techniques. Regular security assessments and vulnerability scanning should be conducted to identify similar issues within the broader system infrastructure.