CVE-2017-18468 in cPanel
Summary
by MITRE
cPanel before 62.0.17 allows demo accounts to execute code via the Htaccess::setphppreference API (SEC-232).
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Analysis
by VulDB Data Team • 07/21/2020
The vulnerability identified as CVE-2017-18468 represents a critical security flaw in cPanel versions prior to 62.0.17 that affects the Htaccess::setphppreference API endpoint. This issue specifically impacts demo accounts and enables unauthorized code execution through a privilege escalation mechanism. The vulnerability stems from insufficient input validation and access control measures within the API interface, allowing malicious actors to manipulate PHP preference settings that should be restricted to authorized users only.
The technical implementation of this vulnerability involves the Htaccess::setphppreference API call which is designed to manage PHP preferences for web directories. However, the flaw occurs when demo accounts can bypass normal access restrictions and invoke this API with malicious parameters. The vulnerability is classified under CWE-284, which deals with improper access control, and specifically relates to insufficient authorization checks within the cPanel administrative interface. Attackers can exploit this by crafting specific API requests that manipulate the PHP execution environment, potentially leading to arbitrary code execution on the server.
The operational impact of CVE-2017-18468 extends beyond simple privilege escalation as it creates a persistent backdoor for attackers to gain full server control. Demo accounts are typically intended to provide limited functionality for demonstration purposes, but this vulnerability allows attackers to elevate privileges and execute arbitrary code with the permissions of the web server. The attack surface is particularly concerning because demo accounts are often accessible to unauthenticated users or those with minimal privileges, making this a significant vector for server compromise. This vulnerability can be mapped to ATT&CK technique T1059.001 for command and scripting interpreter, as it enables execution of malicious scripts through the PHP preference manipulation.
Mitigation strategies for CVE-2017-18468 require immediate implementation of the official cPanel patch version 62.0.17 or later, which addresses the improper access control in the Htaccess::setphppreference API. Organizations should also implement network-level restrictions to limit API access to trusted IP addresses and enforce strict authentication requirements for all API endpoints. Additionally, security monitoring should be enhanced to detect unusual API call patterns and unauthorized access attempts to the Htaccess::setphppreference endpoint. The remediation process must include comprehensive testing of the patched version to ensure that legitimate demo account functionality remains intact while eliminating the code execution vulnerability. Regular security audits of API endpoints and access control mechanisms should be conducted to prevent similar issues from emerging in other components of the cPanel infrastructure.