CVE-2017-18419 in cPanel
Summary
by MITRE
cPanel before 66.0.2 allows stored XSS during WHM cPAddons uninstallation (SEC-266).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2017-18419 represents a critical stored cross-site scripting flaw within cPanel software versions prior to 66.0.2, specifically affecting the WHM cPAddons uninstallation process. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, where malicious input is not properly sanitized before being stored and subsequently executed in users' browsers. The issue manifests during the uninstallation procedure of cPAddons modules within the WHM interface, creating a persistent security risk that can be exploited by attackers to inject malicious scripts into the application's data storage.
The technical exploitation of this vulnerability occurs when an attacker can manipulate input fields during the cPAddons uninstallation process, allowing them to store malicious JavaScript code within the application's database or configuration files. When other users access the affected WHM interface or related administrative functions, their browsers execute the stored malicious code, potentially leading to session hijacking, privilege escalation, or data exfiltration. The vulnerability's impact is amplified because it affects the WHM administrative interface, which typically operates with elevated privileges and access to critical system functions, making it a prime target for attackers seeking to compromise entire hosting environments.
The operational implications of CVE-2017-18419 extend beyond simple script execution, as it can enable attackers to gain unauthorized access to sensitive hosting infrastructure and customer data. Attackers leveraging this vulnerability can potentially steal administrative credentials, modify hosting configurations, or establish persistent backdoors within the cPanel environment. The stored nature of the XSS vulnerability means that the malicious code remains active until manually removed from the system, creating a long-term threat that can affect multiple users over extended periods. This vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, where attackers use stored scripts to maintain access and execute malicious commands within compromised systems.
Organizations affected by this vulnerability should prioritize immediate remediation through updating to cPanel version 66.0.2 or later, which includes proper input sanitization and output encoding mechanisms. Additional mitigations include implementing web application firewalls to monitor for suspicious script patterns, conducting regular security audits of administrative interfaces, and ensuring proper input validation across all user-controllable fields. The vulnerability demonstrates the critical importance of proper security practices in administrative interfaces, where the compromise of a single system can lead to widespread impact across entire hosting environments. Security teams should also implement monitoring for unusual administrative activities and establish incident response procedures specifically addressing stored XSS vulnerabilities in web applications.