CVE-2017-18454 in cPanel
Summary
by MITRE
cPanel before 62.0.24 allows stored XSS in the WHM cPAddons install interface (SEC-262).
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Analysis
by VulDB Data Team • 07/19/2020
The vulnerability CVE-2017-18454 represents a stored cross-site scripting flaw in cPanel software versions prior to 62.0.24, specifically affecting the WHM cPAddons install interface. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is a critical security weakness that allows attackers to inject malicious scripts into web applications that are then executed in the context of other users' browsers. The cPAddons component serves as a package management interface within cPanel's WHM (Web Host Manager) environment, enabling administrators to install and manage third-party software packages on hosting servers.
The technical implementation of this vulnerability occurs when user-supplied input containing malicious script code is stored within the cPAddons installation interface without proper sanitization or validation. When other administrators or users access the affected interface to view the stored data, the malicious scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized administrative actions. The flaw exists because the application fails to properly escape or filter user input before rendering it in the web interface, creating an environment where attacker-controlled content can be persistently stored and later executed.
The operational impact of this vulnerability is significant for hosting providers and system administrators who rely on cPanel for server management. An attacker who can submit malicious input through the cPAddons interface can potentially compromise multiple users who view the affected pages, as the stored script executes in each user's browser context. This creates a persistent threat that can be exploited for extended periods, allowing attackers to steal session cookies, capture login credentials, or perform administrative actions on behalf of legitimate users. The vulnerability is particularly dangerous in shared hosting environments where multiple users access the same management interface.
Mitigation strategies for CVE-2017-18454 include immediate upgrading to cPanel version 62.0.24 or later, which contains the necessary patches to address the stored XSS vulnerability. Organizations should also implement input validation and output encoding mechanisms throughout their web applications to prevent similar issues. The remediation aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1566.001 for credential access through social engineering. Security teams should conduct comprehensive vulnerability assessments to identify any other instances of stored XSS in their cPanel installations and ensure proper web application security controls are in place to prevent unauthorized input processing. Regular security updates and patch management procedures are essential to maintaining the security posture of hosting environments.