CVE-2018-4062 in AirLink ES450
Summary
by MITRE
A hard-coded credentials vulnerability exists in the snmpd function of the Sierra Wireless AirLink ES450 FW 4.9.3. Activating snmpd outside of the WebUI can cause the activation of the hard-coded credentials, resulting in the exposure of a privileged user. An attacker can activate snmpd without any configuration changes to trigger this vulnerability.
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Analysis
by VulDB Data Team • 09/12/2023
The vulnerability identified as CVE-2018-4062 represents a critical hard-coded credentials flaw within the snmpd function of Sierra Wireless AirLink ES450 firmware version 4.9.3. This issue falls under the category of insecure credential storage as classified by CWE-798, where sensitive authentication information is embedded directly within the software code rather than being dynamically generated or securely stored. The affected device operates as a wireless communication gateway that typically manages network connectivity for remote industrial and IoT applications, making it a potentially attractive target for adversaries seeking persistent access to critical infrastructure networks.
The technical implementation of this vulnerability stems from the inclusion of hardcoded SNMP (Simple Network Management Protocol) credentials within the firmware binary. When the snmpd service is activated outside of the standard web-based user interface, these hard-coded credentials are automatically enabled, allowing unauthorized parties to authenticate with elevated privileges. The flaw operates without requiring any configuration modifications, meaning that simply invoking the SNMP daemon service through alternative means triggers the credential exposure. This design flaw creates a persistent backdoor mechanism that remains active regardless of normal system administration practices or security hardening measures.
From an operational impact perspective, this vulnerability creates significant security risks for organizations deploying Sierra Wireless AirLink ES450 devices in their network infrastructure. The exposure of privileged SNMP credentials enables attackers to perform unauthorized network reconnaissance, gain access to sensitive device management functions, and potentially escalate privileges to full administrative control. The vulnerability is particularly concerning because it affects a device commonly used in industrial control systems and remote monitoring applications where network security is paramount. Attackers can leverage this weakness to conduct long-term surveillance, manipulate network configurations, or use the compromised device as a pivot point for attacking other systems within the network perimeter.
The exploitation of this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the initial access and privilege escalation domains. Specifically, the technique maps to T1078 (Valid Accounts) and T1566 (Phishing for Information) where attackers can leverage the hardcoded credentials to establish persistent access. Organizations should implement immediate mitigations including firmware updates to versions that address the hardcoded credential issue, network segmentation to limit access to affected devices, and monitoring for unauthorized SNMP service activation. Additionally, security teams should conduct thorough inventory assessments to identify all affected devices and implement network access controls that restrict SNMP traffic to authorized management systems only. The vulnerability demonstrates the critical importance of proper credential management practices and the dangers of embedding authentication secrets within firmware code without adequate security controls.