CVE-2016-10780 in cPanel
Summary
by MITRE
cPanel before 60.0.25 allows stored XSS in the ftp_sessions API (SEC-180).
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Analysis
by VulDB Data Team • 07/21/2020
The vulnerability CVE-2016-10780 represents a stored cross-site scripting flaw within cPanel software versions prior to 60.0.25, specifically affecting the ftp_sessions API endpoint. This issue resides in the web-based administration interface that system administrators use to manage hosting accounts and server configurations. The vulnerability allows authenticated attackers with access to the cPanel interface to inject malicious scripts that persist in the application's storage and execute when other users view the affected content. The ftp_sessions API handles file transfer protocol session management and user access controls, making it a critical component within the cPanel ecosystem. Stored XSS vulnerabilities are particularly dangerous because malicious payloads remain persistent in the application's database or storage systems, executing automatically whenever affected pages are accessed by legitimate users. The flaw demonstrates a failure in input sanitization and output encoding mechanisms within the API's response handling, creating an attack vector that could compromise user sessions and potentially escalate privileges within the hosting environment.
The technical implementation of this vulnerability involves the improper handling of user-supplied data within the ftp_sessions API endpoint. When legitimate users interact with FTP session management features, the application fails to adequately sanitize or encode input parameters before storing them in the database or rendering them in subsequent user interfaces. This creates an environment where malicious actors can submit crafted payloads through API requests that contain script tags or other malicious code. The stored nature of the vulnerability means that the malicious input is persisted in the application's backend storage, making it available to other users who view the affected session data. Attackers could exploit this by creating FTP sessions with malicious payloads in session names, descriptions, or other configurable fields. The vulnerability aligns with CWE-79 which describes cross-site scripting flaws, and specifically relates to CWE-80 which addresses the storage of untrusted data in web applications. The attack chain typically involves an authenticated user submitting malicious input through the API, which gets stored in the database, and then executed when other users view the session information in the cPanel interface.
The operational impact of CVE-2016-10780 extends beyond simple script execution, potentially enabling attackers to perform session hijacking, data exfiltration, and privilege escalation within the cPanel environment. When malicious scripts execute in users' browsers, attackers can steal session cookies, access sensitive account information, or redirect users to malicious websites. The vulnerability affects the entire hosting infrastructure since cPanel serves as the primary interface for managing multiple hosting accounts and domains. An attacker who successfully exploits this vulnerability can compromise the security of multiple accounts if they have access to shared hosting environments or can manipulate the FTP session data for legitimate users. The impact is particularly severe in shared hosting environments where multiple customers share the same cPanel instance, as a single compromised session could potentially affect all users of that instance. The vulnerability also creates opportunities for attackers to establish persistent backdoors or perform reconnaissance activities within the hosting environment, making it a significant concern for system administrators managing critical web hosting infrastructure.
Mitigation strategies for CVE-2016-10780 require immediate implementation of software updates and comprehensive input validation measures. The primary remediation involves upgrading cPanel to version 60.0.25 or later, which includes patches addressing the stored XSS vulnerability in the ftp_sessions API. System administrators should also implement additional defensive measures such as enhanced input filtering, output encoding, and regular security auditing of API endpoints. The implementation should follow security best practices including the principle of least privilege, where API access is restricted to authorized users only, and comprehensive logging of API activities to detect potential exploitation attempts. Organizations should also consider implementing web application firewalls and content security policies to add additional layers of protection against similar vulnerabilities. The vulnerability demonstrates the importance of maintaining up-to-date software versions and following security patches promptly, as highlighted by the ATT&CK framework's emphasis on maintaining up-to-date systems and the exploitation of known vulnerabilities. Regular security assessments and penetration testing of web applications should be conducted to identify and remediate similar stored XSS vulnerabilities across the entire hosting infrastructure.