CVE-2023-6874 in GSDK
Summary
by MITRE • 02/05/2024
Prior to v7.4.0, Ember ZNet is vulnerable to a denial of service attack through manipulation of the NWK sequence number
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Analysis
by VulDB Data Team • 09/26/2024
The vulnerability identified as CVE-2023-6874 affects Ember ZNet software versions prior to v7.4.0, presenting a significant denial of service risk through manipulation of the Network (NWK) sequence number. This flaw resides within the Zigbee network protocol implementation that governs communication between devices in wireless mesh networks. The NWK sequence number serves as a critical mechanism for ensuring message integrity and preventing duplicate transmissions within the Zigbee stack. When an attacker can manipulate this sequence number, they gain the ability to disrupt normal network operations and potentially cause complete service interruption. The vulnerability stems from insufficient validation of sequence number values during network packet processing, allowing malicious actors to craft packets with manipulated sequence numbers that can cause the network coordinator or end devices to reject legitimate communications or enter unstable states.
The technical exploitation of this vulnerability occurs through the manipulation of the NWK sequence number field within Zigbee network layer packets. This field typically contains an 8-bit value that increments with each transmitted packet to maintain order and prevent duplicates. When the Ember ZNet implementation fails to properly validate or handle sequence number anomalies, attackers can exploit this weakness by sending packets with sequence numbers that fall outside expected ranges or that create artificial gaps in the sequence. The flaw creates a condition where legitimate network traffic becomes corrupted or rejected, leading to a cascading failure that can render the entire Zigbee network unusable. This type of vulnerability aligns with CWE-129, which addresses improper validation of input ranges, and represents a classic example of insufficient input validation in network protocol implementations. The attack vector is particularly concerning because it requires minimal privileges and can be executed remotely, making it accessible to attackers who merely need to intercept or inject network traffic.
The operational impact of CVE-2023-6874 extends beyond simple service disruption to encompass complete network paralysis and potential security compromise. In industrial automation environments, smart home systems, or IoT deployments using Ember ZNet, this vulnerability can lead to catastrophic failures where critical devices become unreachable or communications break down entirely. The denial of service can persist until network devices are manually reset or the software is updated to a patched version. For organizations relying on Zigbee-based systems for security monitoring, lighting control, or industrial process automation, this vulnerability represents a serious risk to operational continuity. The attack can be particularly devastating in environments where network reliability is paramount, such as healthcare facilities, manufacturing plants, or smart building systems. According to ATT&CK framework, this vulnerability maps to T1499.004 which covers network denial of service attacks, and T1566.001 which addresses spearphishing via social engineering, as attackers might exploit this weakness to gain unauthorized access to network control points.
Organizations should immediately implement mitigation strategies that include updating to Ember ZNet version 7.4.0 or later, which contains the necessary patches to address the sequence number validation issues. Network segmentation and monitoring should be enhanced to detect anomalous sequence number patterns that may indicate exploitation attempts. Additionally, implementing intrusion detection systems capable of identifying suspicious network traffic patterns related to Zigbee protocol violations can provide early warning of potential attacks. The vulnerability also highlights the importance of robust input validation in embedded systems and network protocols, emphasizing that even seemingly simple fields like sequence numbers require careful consideration in security design. Security teams should conduct thorough assessments of their Zigbee network infrastructure to identify devices running vulnerable versions of Ember ZNet and prioritize their remediation. Regular security audits of network protocol implementations and maintaining up-to-date firmware across all Zigbee devices will help prevent similar vulnerabilities from being exploited in the future.