CVE-2022-31499 in eMerge E3
Summary
by MITRE • 08/26/2022
Nortek Linear eMerge E3-Series devices before 0.32-08f allow an unauthenticated attacker to inject OS commands via ReaderNo. NOTE: this issue exists because of an incomplete fix for CVE-2019-7256.
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Analysis
by VulDB Data Team • 10/02/2022
The vulnerability CVE-2022-31499 affects Nortek Linear eMerge E3-Series access control devices running firmware versions prior to 0.32-08f, representing a critical command injection flaw that permits unauthenticated remote exploitation. This vulnerability specifically targets the ReaderNo parameter within the device's web interface, allowing attackers to execute arbitrary operating system commands without requiring authentication credentials. The flaw demonstrates a concerning pattern of incomplete security remediation, as it stems from a regression or insufficient fix for the previously disclosed CVE-2019-7256, indicating poor vulnerability management practices within the vendor's development lifecycle. This represents a significant security regression that undermines previous security efforts and leaves devices exposed to remote exploitation by threat actors who may not require any credentials to compromise the system.
The technical implementation of this vulnerability involves improper input validation within the web application layer of the eMerge E3-Series devices, where the ReaderNo parameter fails to properly sanitize user-supplied input before processing. When an attacker submits malicious input through this parameter, the system directly incorporates the unvalidated data into operating system commands without adequate filtering or escaping mechanisms. This type of vulnerability maps directly to CWE-77, which specifically addresses command injection flaws in software applications that execute operating system commands based on user input. The vulnerability exists within the device's web server component that handles HTTP requests and processes configuration parameters, making it accessible over the network without requiring physical access or authentication.
The operational impact of this vulnerability is severe and multifaceted, as it allows attackers to achieve complete system compromise of affected devices. Successful exploitation enables adversaries to execute arbitrary code with the privileges of the web application user, typically root or administrator level access to the underlying operating system. Attackers can leverage this capability to install backdoors, exfiltrate sensitive access control data, modify device configurations, or establish persistent access points within the network infrastructure. The vulnerability particularly impacts enterprise environments that rely on these access control systems for physical security, potentially allowing attackers to bypass physical security measures and gain unauthorized access to facilities. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically the execution of operating system commands, and T1566 for credential harvesting through social engineering or system compromise.
Organizations should immediately implement comprehensive mitigation strategies to address this vulnerability, beginning with mandatory firmware updates to version 0.32-08f or later releases that contain the corrected implementation. Network segmentation should be enforced to limit access to these devices to authorized personnel only, while implementing firewalls and access control lists to restrict HTTP and HTTPS traffic to necessary administrative addresses. Regular security assessments should include vulnerability scanning of access control systems to identify unpatched devices, and network monitoring should be enhanced to detect anomalous command execution patterns. Additionally, device hardening practices should be implemented, including disabling unnecessary services, enforcing strong authentication mechanisms, and maintaining detailed audit logs of all administrative activities. The vulnerability underscores the importance of proper vulnerability remediation processes and the dangers of incomplete fixes that leave systems exposed to continued exploitation.