CVE-2018-5439 in Linear eMerge E3
Summary
by MITRE
A Command Injection issue was discovered in Nortek Linear eMerge E3 series Versions V0.32-07e and prior. A remote attacker may be able to execute arbitrary code on a target machine with elevated privileges.
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Analysis
by VulDB Data Team • 01/07/2020
The vulnerability identified as CVE-2018-5439 represents a critical command injection flaw within the Nortek Linear eMerge E3 series security devices running firmware versions V0.32-07e and earlier. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before incorporating it into system commands. The affected devices are part of the industrial security ecosystem designed for access control and building management systems, making them attractive targets for adversaries seeking persistent access to critical infrastructure environments.
The technical exploitation of this vulnerability occurs through the manipulation of command execution parameters within the device's web interface or API endpoints. Attackers can craft malicious inputs that bypass authentication mechanisms and inject arbitrary shell commands into the underlying operating system. This command injection flaw operates at the application layer and can be leveraged to execute code with the privileges of the web server process, which typically runs with elevated permissions on these industrial devices. The vulnerability's classification aligns with CWE-77 and CWE-88 within the Common Weakness Enumeration framework, specifically addressing improper input validation and command injection attack vectors.
The operational impact of CVE-2018-5439 extends beyond simple remote code execution, as it enables attackers to gain full administrative control over the affected security devices. Once compromised, these devices can be used as launching points for further attacks within the network infrastructure, potentially allowing lateral movement to other systems and unauthorized access to sensitive building management data. The vulnerability affects industrial control systems that often operate in isolated environments, making detection and response more challenging for security teams. This threat aligns with ATT&CK techniques such as T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation.
Mitigation strategies for this vulnerability require immediate firmware updates from Nortek Linear to address the command injection flaw through proper input sanitization and parameter validation. Organizations should implement network segmentation to isolate these devices from critical network segments and deploy intrusion detection systems to monitor for suspicious command execution patterns. Additional protective measures include disabling unnecessary network services, implementing strong access controls, and conducting regular security assessments of industrial control systems. The vulnerability demonstrates the critical importance of secure coding practices in industrial environments where security flaws can have significant operational and safety implications beyond traditional information technology concerns.