CVE-2017-18471 in cPanel
Summary
by MITRE
cPanel before 62.0.4 allows self XSS on the paper_lantern password-change screen (SEC-197).
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Analysis
by VulDB Data Team • 07/21/2020
The vulnerability identified as CVE-2017-18471 represents a critical self cross-site scripting flaw discovered in cPanel versions prior to 62.0.4, specifically affecting the paper_lantern theme's password change interface. This issue falls under the CWE-79 category of Cross-Site Scripting, where the application fails to properly sanitize user input before rendering it back to the browser. The vulnerability exists within the password change screen of the paper_lantern theme, which is a widely used interface for cPanel administrators and users managing their hosting accounts. The self XSS nature indicates that an attacker can inject malicious scripts that execute within the context of the victim's own browser session, potentially compromising the user's account credentials and access privileges.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the password change form processing logic. When users submit password change requests through the paper_lantern interface, the application fails to properly escape or filter special characters in the input fields before displaying them back to the user. This allows an attacker to craft malicious payloads that, when entered by an unsuspecting user, execute within the victim's browser session. The vulnerability specifically affects the password change screen, making it particularly dangerous as it targets users who are already authenticated and potentially privileged within the cPanel environment. Attackers can leverage this weakness to execute arbitrary JavaScript code that could steal session cookies, redirect users to malicious sites, or perform unauthorized actions on behalf of the victim.
The operational impact of CVE-2017-18471 extends beyond simple data theft, as it provides attackers with a potential foothold for more extensive compromise within the cPanel environment. The self XSS vulnerability enables attackers to execute code in the context of the authenticated user's session, potentially allowing them to access sensitive administrative functions, modify account settings, or exfiltrate confidential information. This vulnerability directly maps to ATT&CK technique T1059.007 for JavaScript execution and T1531 for account access through session hijacking. The attack vector is particularly concerning because it targets the password change functionality, which is frequently used by administrators and users who may be more trusting of the interface. The vulnerability could be exploited through various methods including social engineering, where attackers convince users to enter malicious payloads in the password change form, or through compromised user accounts that are then used to deliver the malicious payloads.
Mitigation strategies for CVE-2017-18471 focus primarily on updating to cPanel version 62.0.4 or later, which includes proper input sanitization and output encoding fixes for the affected password change screen. Organizations should implement comprehensive patch management procedures to ensure all cPanel installations are updated promptly. Additionally, network administrators should monitor for any suspicious activity related to password change requests and implement web application firewalls to detect and block malicious payloads. The vulnerability demonstrates the importance of proper input validation and output encoding practices, which aligns with security standards such as OWASP Top Ten A03:2021 - Injection and CWE-79. Administrators should also consider implementing multi-factor authentication as an additional security layer, as this vulnerability primarily affects authenticated sessions. Regular security audits and penetration testing of cPanel installations can help identify similar vulnerabilities in other components of the web hosting environment, ensuring comprehensive protection against similar attack vectors.