CVE-2016-10777 in cPanel
Summary
by MITRE
cPanel before 60.0.25 allows self XSS in WHM Tweak Settings for autodiscover_host (SEC-177).
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Analysis
by VulDB Data Team • 07/21/2020
The vulnerability identified as CVE-2016-10777 represents a self-cross-site scripting flaw within cPanel's WHM Tweak Settings interface, specifically affecting versions prior to 60.0.25. This issue resides in the autodiscover_host configuration parameter handling, where insufficient input validation and output sanitization allow malicious actors to inject malicious scripts into the web interface. The vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically manifesting as a self-XSS variant where the attack vector targets the authenticated user within their own session context.
The technical implementation of this vulnerability occurs within the WHM administrative interface where the autodiscover_host setting is processed and rendered without proper HTML encoding or sanitization of user-supplied input. When administrators navigate to the Tweak Settings section and modify this parameter, the system fails to properly escape special characters in the input field, allowing script tags or other malicious payloads to be stored and subsequently executed within the context of the administrator's browser session. This creates a dangerous scenario where any administrator who accesses the affected configuration page becomes a potential victim of their own session.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with a means to escalate privileges and conduct more sophisticated attacks within the cPanel environment. While the vulnerability is classified as self-XSS, it can serve as a stepping stone for more serious compromises, particularly when combined with other vulnerabilities or when administrators are tricked into interacting with maliciously crafted configuration settings. The attack typically requires social engineering to convince administrators to input malicious content into the affected field, but once executed, it can potentially allow attackers to perform actions as the administrator, including modifying system configurations, accessing sensitive data, or conducting further reconnaissance.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, beginning with immediate patching of affected cPanel installations to version 60.0.25 or later. Organizations should also consider implementing Content Security Policy headers to limit script execution within the WHM interface, though this measure alone is insufficient given the self-XSS nature of the vulnerability. Regular security awareness training for administrators is crucial to prevent social engineering attacks that may exploit this vulnerability. Additionally, monitoring for unusual configuration changes and implementing proper input validation at multiple layers of the application can help detect and prevent exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.006 for Command and Scripting Interpreter, specifically focusing on script execution within web interfaces, and demonstrates the importance of proper input sanitization and output encoding as outlined in the OWASP Top Ten Project's prevention guidelines.