CVE-2018-4072 in AirLink ES450
Summary
by MITRE
An exploitable Permission Assignment vulnerability exists in the ACEManager EmbeddedAceSet_Task.cgi functionality of Sierra Wireless AirLink ES450 FW 4.9.3. The EmbeddedAceSet_Task.cgi executable is used to change MSCII configuration values within the configuration manager of the AirLink ES450. This binary does not have any restricted configuration settings, so once the MSCIID is discovered, any authenticated user can send configuration changes using the /cgi-bin/Embedded_Ace_Set_Task.cgi endpoint.
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Analysis
by VulDB Data Team • 09/12/2023
The CVE-2018-4072 vulnerability represents a critical permission assignment flaw within the Sierra Wireless AirLink ES450 firmware version 4.9.3, specifically affecting the ACEManager EmbeddedAceSet_Task.cgi component. This vulnerability resides in the embedded web interface configuration management system that controls various modem settings through the MSCII (Modem System Configuration Interface) framework. The flaw manifests when the system fails to properly enforce access controls on configuration modification endpoints, allowing unauthorized privilege escalation through simple authenticated requests. The vulnerability is particularly concerning as it operates at the core of device configuration management, where legitimate administrative functions are exposed without proper authorization checks, creating a pathway for malicious actors to manipulate critical network parameters.
The technical implementation of this vulnerability stems from the absence of proper access control mechanisms within the EmbeddedAceSet_Task.cgi executable, which serves as the primary interface for modifying MSCII configuration values. This binary lacks any form of restricted configuration validation or user privilege verification, meaning that once an attacker discovers a valid MSCIID, they can submit arbitrary configuration changes through the designated endpoint at /cgi-bin/Embedded_Ace_Set_Task.cgi. The vulnerability classifies under CWE-285 Permission Assignment, which specifically addresses issues where system components fail to properly enforce access controls or authorization mechanisms. The flaw essentially allows any authenticated user to perform administrative operations that should typically require elevated privileges, creating a fundamental breakdown in the principle of least privilege and potentially enabling complete device compromise through configuration manipulation.
The operational impact of CVE-2018-4072 extends beyond simple unauthorized configuration changes, as it provides attackers with the capability to fundamentally alter network connectivity parameters, security settings, and operational behaviors of the AirLink ES450 device. An attacker could potentially disable security features, modify network access controls, change authentication settings, or redirect network traffic through manipulated MSCII configurations. This vulnerability directly maps to ATT&CK technique T1068, which involves exploiting legitimate credentials to gain access to systems with elevated privileges, and T1566, which focuses on the manipulation of network infrastructure components. The implications for network security are severe, as compromised AirLink ES450 devices could serve as entry points for broader network infiltration, provide persistent backdoors, or enable man-in-the-middle attacks against connected systems, particularly in industrial environments where these devices often serve as critical communication links.
Mitigation strategies for CVE-2018-4072 should focus on both immediate remediation and long-term security hardening measures. The most effective immediate solution involves updating the firmware to a patched version that implements proper access controls and authentication checks within the EmbeddedAceSet_Task.cgi functionality. Organizations should also implement network segmentation to limit access to these administrative endpoints, restrict network access based on IP address whitelisting, and enforce strong authentication mechanisms with multi-factor authentication where possible. Additionally, network monitoring should be enhanced to detect unusual configuration change patterns, and regular security audits should verify that no unauthorized modifications have occurred. The vulnerability highlights the importance of implementing proper input validation and access control checks in embedded systems, aligning with security best practices outlined in NIST SP 800-53 and ISO 27001 standards for secure system development and operational security management.