CVE-2021-37604 in MiWi
Summary
by MITRE • 08/05/2021
In the Microchip MiWi v6.5 software stack, there is a possibility of frame counters being validated/updated prior to message authentication.
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Analysis
by VulDB Data Team • 08/10/2021
The vulnerability identified as CVE-2021-37604 resides within the Microchip MiWi v6.5 software stack, a widely utilized wireless communication protocol implementation for embedded systems and Internet of Things deployments. This issue represents a critical flaw in the cryptographic message authentication process that directly impacts the security integrity of wireless communications. The vulnerability specifically affects the order of operations during frame counter validation and message authentication procedures, creating a window where frame counters can be processed before the corresponding message authentication checks occur.
The technical flaw manifests as a timing attack vector that exploits the improper sequence of cryptographic operations within the wireless protocol stack. In normal operation, frame counters should be validated and updated only after successful message authentication to prevent replay attacks and ensure message integrity. However, the MiWi v6.5 implementation processes frame counter validation and updates before message authentication verification, allowing potential attackers to manipulate the frame counter state prior to authentication checks. This sequence violation creates a condition where malicious actors can potentially reuse frame counter values or manipulate the counter state to bypass authentication mechanisms.
The operational impact of this vulnerability extends across numerous embedded systems and IoT deployments that rely on Microchip's MiWi stack for secure wireless communication. Systems utilizing this software stack may experience compromised message integrity, potential replay attacks, and weakened cryptographic protections that could lead to unauthorized access or data manipulation. The vulnerability affects devices operating in various security-sensitive environments including industrial control systems, smart grid implementations, and wireless sensor networks where proper frame counter management is crucial for maintaining communication security. Organizations deploying affected systems may face increased risk of man-in-the-middle attacks, message replay scenarios, and overall degradation of the security posture of their wireless networks.
This vulnerability aligns with CWE-310, which addresses cryptographic weaknesses in the order of operations during cryptographic processing, and represents a specific implementation flaw in the cryptographic protocol stack. The issue also maps to ATT&CK technique T1566, which covers social engineering and credential access through manipulation of authentication mechanisms. Mitigation strategies should include immediate software updates from Microchip addressing the frame counter validation sequence, implementation of additional authentication layers, and monitoring for anomalous frame counter behavior. Organizations should conduct comprehensive security assessments of their deployed MiWi v6.5 systems, implement network segmentation to limit attack surface, and consider deploying intrusion detection systems to monitor for potential exploitation attempts. Additionally, system administrators should establish robust monitoring procedures for frame counter anomalies and implement proper access controls to minimize the impact of potential exploitation.