CVE-2022-40536 in 315 5G IoT Modem
Summary
by MITRE • 06/06/2023
Transient DOS due to improper authentication in modem while receiving plain TLB OTA request message from network.
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Analysis
by VulDB Data Team • 06/06/2023
The vulnerability identified as CVE-2022-40536 represents a transient denial of service condition affecting modem firmware implementations that handle over-the-air communication protocols. This weakness occurs during the processing of plain TLB OTA request messages received from network infrastructure, specifically manifesting when the modem fails to properly authenticate incoming requests before proceeding with message handling operations. The issue stems from inadequate validation mechanisms within the modem's authentication framework, creating a window where malicious or malformed requests can disrupt normal operational procedures. This vulnerability is particularly concerning within mobile network environments where modems serve as critical communication endpoints for device connectivity and data transmission services.
The technical flaw manifests through improper authentication handling during the reception of TLB OTA messages, which are typically used for firmware updates, configuration changes, or network parameter modifications. When a modem receives such a message without adequate authentication verification, it may proceed with processing operations that can lead to system instability or complete service interruption. The transient nature of this denial of service indicates that while the system may recover automatically after the attack vector is removed, the temporary disruption can still cause significant operational impacts including dropped connections, failed communications, and service degradation for end users. The vulnerability specifically affects the modem's state machine and message processing logic, where authentication checks are either bypassed entirely or executed incorrectly, leading to unpredictable behavior during message handling.
Operational impact of this vulnerability extends beyond simple service interruption to potentially compromise network reliability and user experience across affected mobile devices and network infrastructure. Mobile network operators may experience increased call drops, failed data connections, and reduced service availability during periods when malicious OTA messages are transmitted to vulnerable modems. The transient nature of the attack means that network administrators must maintain continuous monitoring capabilities to detect and respond to these disruptions, as the effects may not be immediately apparent or persistent. Organizations relying on modem-based communication systems for critical operations face potential business continuity risks, as even brief service interruptions can have cascading effects on dependent systems and services. The vulnerability affects both consumer and enterprise mobile devices, making it particularly widespread in scope and impact across various network environments.
Mitigation strategies for CVE-2022-40536 should focus on strengthening authentication mechanisms within modem firmware implementations and implementing robust message validation procedures. Network operators should prioritize firmware updates from manufacturers addressing this specific vulnerability, ensuring that all affected modems receive security patches that properly validate OTA message authenticity before processing. System administrators should consider implementing network-level filtering mechanisms to identify and block suspicious OTA message patterns, while also establishing monitoring protocols to detect unusual authentication failure patterns that may indicate exploitation attempts. The implementation of secure boot processes and cryptographic authentication methods can help prevent unauthorized OTA messages from being processed by vulnerable modems. Organizations should also develop incident response procedures specifically addressing transient denial of service conditions, including automated detection capabilities and rapid remediation protocols. This vulnerability aligns with CWE-287, which addresses improper authentication issues, and may be categorized under ATT&CK technique T1566 for credential harvesting and T1499 for endpoint denial of service, highlighting its potential for both authentication bypass and service disruption attacks within mobile network environments.