CVE-2018-20912 in cPanel
Summary
by MITRE
cPanel before 70.0.23 allows demo accounts to execute code via awstats (SEC-362).
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Analysis
by VulDB Data Team • 07/18/2020
The vulnerability identified as CVE-2018-20912 represents a critical security flaw in cPanel versions prior to 70.0.23 that enables demo accounts to execute arbitrary code through the awstats component. This issue falls under the category of privilege escalation and code execution vulnerabilities, specifically targeting the web-based control panel used by hosting providers to manage their servers and customer accounts. The vulnerability is particularly concerning because it allows unprivileged demo users to gain elevated privileges and execute malicious code on the target system.
The technical flaw resides in the awstats integration within cPanel's demo account functionality. When demo accounts access certain awstats features, the system fails to properly validate user input and sanitize parameters passed to the underlying awstats processing mechanisms. This lack of proper input validation creates a path for command injection attacks where malicious input can be interpreted and executed as system commands. The vulnerability is classified as a command injection flaw under CWE-77 and represents a specific instance of CWE-94, which deals with the execution of arbitrary code or commands. The issue stems from insufficient sanitization of user-supplied data that flows into system command execution contexts.
The operational impact of this vulnerability extends beyond simple privilege escalation as it allows attackers to gain full control over the compromised system. Demo accounts typically have limited access rights and are designed to provide temporary user experience without posing significant security risks. However, this vulnerability enables attackers to bypass these restrictions and execute arbitrary code with the privileges of the web server process. This can lead to complete system compromise, data exfiltration, and potential lateral movement within the network. The vulnerability also aligns with ATT&CK technique T1059.001, which covers command and scripting interpreter execution, and T1068, which involves privilege escalation through local exploits.
Organizations running cPanel versions prior to 70.0.23 face significant security risks as this vulnerability can be exploited by anyone with access to a demo account. The exploitation process typically involves crafting malicious input that gets processed by the awstats component and subsequently executed as system commands. This type of vulnerability is particularly dangerous in shared hosting environments where multiple customers share the same infrastructure and where demo accounts are commonly used for testing purposes. The vulnerability also demonstrates the importance of proper input validation and the principle of least privilege in system design, as it highlights how insufficient validation in one component can lead to complete system compromise. Organizations should immediately update to cPanel version 70.0.23 or later to remediate this vulnerability, as the patch addresses the input validation issues in the awstats integration and implements proper sanitization of user-supplied data before processing.