CVE-2017-11441 in cPanel
Summary
by MITRE
The WHM Upload Locale interface in cPanel before 56.0.51, 58.x before 58.0.52, 60.x before 60.0.45, 62.x before 62.0.27, 64.x before 64.0.33, and 66.x before 66.0.2 has XSS via a locale filename, aka SEC-297.
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Analysis
by VulDB Data Team • 10/27/2019
The vulnerability identified as CVE-2017-11441 represents a cross-site scripting flaw within the WHM Upload Locale interface of cPanel software versions prior to specific patched releases. This security weakness exists in the handling of locale filenames during the upload process, where user-supplied input is not properly sanitized before being rendered in the web interface. The vulnerability affects multiple major release branches including 56.x, 58.x, 60.x, 62.x, 64.x, and 66.x versions, indicating a widespread issue that impacted a significant portion of cPanel installations during that timeframe. The flaw specifically manifests when users upload locale files through the WHM interface, making it particularly concerning for system administrators who rely on this functionality for internationalization purposes.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within the cPanel web application. When a user uploads a locale file, the system processes the filename and displays it within the web interface without proper sanitization of potentially malicious content. This creates an environment where attackers can inject malicious scripts that execute in the context of other users' browsers who view the affected interface. The vulnerability is classified as a classic XSS flaw, specifically aligning with CWE-79 which describes improper neutralization of input during web page generation. The attack vector is particularly insidious because it leverages the legitimate upload functionality that administrators would normally trust, making it difficult to detect and prevent through traditional security measures.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to impersonate legitimate users within the cPanel environment. An attacker who successfully exploits this vulnerability could potentially steal session cookies, modify user permissions, or gain access to sensitive administrative functions through the compromised browser sessions. The vulnerability affects the WHM (Web Host Manager) interface specifically, which is used by hosting administrators to manage server configurations, user accounts, and system settings. This makes the potential impact particularly severe for hosting providers and system administrators who rely on cPanel for their operations, as successful exploitation could lead to complete compromise of the hosting environment. The vulnerability also aligns with ATT&CK technique T1059.001 which covers command and scripting interpreter, as the XSS payload could potentially be used to execute additional malicious commands within the browser context.
Mitigation strategies for this vulnerability require immediate patching of affected cPanel installations to versions 56.0.51, 58.0.52, 60.0.45, 62.0.27, 64.0.33, and 66.0.2 or later. Organizations should also implement additional security measures including input validation at multiple layers, output encoding for all user-supplied data, and regular security audits of web applications. Network segmentation and monitoring of upload activities can help detect potential exploitation attempts. The vulnerability demonstrates the importance of secure input handling in web applications and highlights the need for comprehensive security testing throughout the software development lifecycle. Security professionals should also consider implementing web application firewalls and content security policies to provide additional protection against similar vulnerabilities in the future. The incident underscores the critical nature of keeping web applications updated with the latest security patches and the potential consequences of failing to address known vulnerabilities in widely used software platforms.