CVE-2017-18455 in cPanel
Summary
by MITRE
In cPanel before 62.0.17, addon domain conversion did not require a package for resellers (SEC-208).
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Analysis
by VulDB Data Team • 07/19/2020
The vulnerability described in CVE-2017-18455 represents a critical authorization and access control flaw within the cPanel web hosting management platform. This issue specifically affects versions prior to 62.0.17 and relates to the improper handling of addon domain conversions when performed by reseller accounts. The core problem lies in the absence of mandatory package validation during the addon domain conversion process, creating a significant security gap that could be exploited by malicious actors. From a cybersecurity perspective, this vulnerability directly impacts the principle of least privilege and proper access control mechanisms that should govern administrative operations within hosting environments.
The technical implementation flaw stems from the cPanel reseller account functionality where addon domain conversion operations do not enforce package requirements that would normally be mandatory for such administrative actions. This means that reseller accounts could potentially convert addon domains without proper resource allocation or package constraints that would typically govern such operations. The vulnerability creates a pathway for privilege escalation or unauthorized resource consumption where resellers might gain access to functionality they should not have, potentially leading to unauthorized domain management or resource allocation. This issue falls under the category of inadequate input validation and access control enforcement, which aligns with CWE-284 Access Control Issues and CWE-305 Authentication Issues. The flaw essentially allows for unauthorized administrative operations that should require proper authorization and resource provisioning.
The operational impact of this vulnerability extends beyond simple access control violations and can result in significant resource abuse and potential service disruption within hosting environments. Resellers exploiting this vulnerability could convert addon domains without proper package constraints, leading to unauthorized resource consumption, potential denial of service conditions, and compromise of hosting account integrity. The vulnerability affects the overall security posture of cPanel installations and could enable attackers to escalate privileges or gain unauthorized access to additional hosting resources. From an attacker's perspective, this represents a low-effort method to bypass security controls that should normally prevent unauthorized administrative actions, making it particularly concerning for shared hosting environments where multiple resellers manage accounts. The vulnerability also impacts compliance with industry standards such as NIST SP 800-53 and ISO 27001 controls related to access control and privilege management.
Mitigation strategies for CVE-2017-18455 primarily focus on immediate patching of cPanel installations to version 62.0.17 or later, which resolves the package validation issue during addon domain conversions. Organizations should also implement additional monitoring of reseller account activities, particularly around domain management operations, to detect anomalous behavior that might indicate exploitation attempts. Network segmentation and proper access control policies should be enforced to limit the potential impact of any successful exploitation attempts. Security teams should conduct regular audits of reseller account permissions and ensure that proper package constraints are enforced for all administrative operations. The vulnerability demonstrates the importance of maintaining up-to-date software versions and proper access control enforcement, with implications for ATT&CK techniques related to privilege escalation and defense evasion. Organizations should also consider implementing automated patch management processes to ensure timely remediation of similar vulnerabilities. The incident highlights the need for comprehensive security testing of administrative interfaces and proper validation of all user operations within hosting platforms.