CVE-2016-10851 in cPanel
Summary
by MITRE
cPanel before 11.54.0.4 allows self XSS in the WHM PHP Configuration editor interface (SEC-84).
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Analysis
by VulDB Data Team • 11/20/2023
The vulnerability CVE-2016-10851 represents a critical self cross-site scripting flaw discovered in cPanel versions prior to 11.54.0.4 within the WHM PHP Configuration editor interface. This security weakness falls under the category of CWE-79 which specifically addresses cross-site scripting vulnerabilities, making it a significant concern for web application security. The flaw allows authenticated users with access to the WHM interface to inject malicious scripts that execute in the context of their own browser session, creating a self-XSS vector that can be exploited to compromise user sessions and potentially escalate privileges within the cPanel environment.
The technical implementation of this vulnerability occurs within the PHP Configuration editor component of WHM, where user input is not properly sanitized or escaped before being rendered back to the browser. When administrators or users modify PHP configuration settings through this interface, the system fails to adequately validate or encode the input data, allowing malicious payloads to be stored and subsequently executed when the configuration page is accessed again. This creates a persistent XSS attack vector that can be triggered by any user with sufficient privileges to access the WHM PHP Configuration editor, typically administrators or users with root-level access to the cPanel environment.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with potential access to sensitive system configurations and user data. Since WHM represents the Web Host Manager interface with elevated privileges, successful exploitation could allow attackers to view or modify critical PHP settings that affect the entire hosting environment. The self-XSS nature of this vulnerability means that the attack vector is particularly dangerous as it can be executed by the victim themselves, potentially leading to session hijacking, credential theft, or unauthorized configuration changes that could compromise multiple websites hosted on the same server. This vulnerability directly aligns with ATT&CK technique T1059.007 for command and script injection, and T1548.002 for abuse of privileges.
Mitigation strategies for CVE-2016-10851 require immediate implementation of the vendor-provided security patch available in cPanel version 11.54.0.4 and subsequent releases. Organizations should prioritize updating their cPanel installations to the latest stable version while implementing additional defensive measures including enhanced input validation and output encoding within the affected interface. Security administrators should also consider implementing web application firewalls to detect and block suspicious script injection attempts, as well as monitoring for unauthorized configuration changes within the WHM environment. Regular security audits of cPanel configurations and access controls should be conducted to ensure that only authorized personnel have access to sensitive administrative interfaces, reducing the potential attack surface for such vulnerabilities. The remediation process should include thorough testing of the updated environment to ensure that legitimate functionality remains intact while the XSS vulnerability is properly addressed.