CVE-2016-10823 in cPanel
Summary
by MITRE
cPanel before 55.9999.141 allows arbitrary code execution in the context of the root account because of MakeText interpolation (SEC-89).
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Analysis
by VulDB Data Team • 11/20/2023
The vulnerability identified as CVE-2016-10823 represents a critical arbitrary code execution flaw within cPanel software versions prior to 55.9999.141. This security weakness stems from improper input validation and handling within the MakeText interpolation mechanism, creating a dangerous condition where malicious actors can inject and execute arbitrary commands with the highest possible privileges. The flaw exists in the core functionality of cPanel's text processing system, which is widely used for generating configuration files and managing system operations across numerous hosting environments.
The technical implementation of this vulnerability leverages a specific interpolation flaw in the MakeText function that processes user-supplied data without adequate sanitization or validation. When cPanel processes text templates containing user input, the interpolation mechanism fails to properly escape or validate special characters that could be interpreted as command sequences. This creates an environment where an attacker can inject malicious payloads that get executed in the root account context, effectively providing complete system compromise. The vulnerability specifically affects the way cPanel handles template variables and dynamic content generation, making it particularly dangerous in multi-tenant hosting environments where multiple users share the same infrastructure.
The operational impact of this vulnerability is severe and far-reaching, as it allows attackers to achieve complete system control with root privileges. Once exploited, the attacker gains unrestricted access to all system resources, including the ability to modify or delete critical files, create new user accounts, install malicious software, and potentially escalate to other connected systems within the network. The root account context provides access to all system configurations, databases, and sensitive information stored on the server, making this vulnerability particularly attractive to cybercriminals. The widespread adoption of cPanel across hosting providers means that exploitation could affect thousands of systems simultaneously, creating a significant risk to internet infrastructure security.
This vulnerability aligns with CWE-15 (External Control of System or Configuration Setting) and CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component) in the Common Weakness Enumeration catalog, indicating improper handling of external input and inadequate output sanitization. From the MITRE ATT&CK framework perspective, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1068 (Exploitation for Privilege Escalation) techniques, as it enables command execution and privilege escalation to the root level. Organizations should immediately implement the vendor-provided patch for cPanel version 55.9999.141 or later, which addresses the MakeText interpolation issue through proper input validation and sanitization mechanisms. Additional mitigations include restricting access to cPanel administrative interfaces, implementing network segmentation, and monitoring for suspicious command execution patterns in system logs.