CVE-2025-2329 is a medium severity vulnerability identified in Silicon Labs' OpenThread Radio Co-Processor (RCP) implementations, specifically affecting versions 2.5.0, 2.6.0, and an unspecified version labeled '0'. The vulnerability is classified under CWE-908, which pertains to the use of uninitialized resources. In this case, under high traffic conditions, the OpenThread RCP fails to properly clear the SPI (Serial Peripheral Interface) transmit buffer before sending data to its host processor. This results in the transmission of corrupt packets over the SPI interface. When the host receives these corrupt packets, it triggers a reset of the RCP, causing a denial of service (DoS) condition. The vulnerability does not require authentication, user interaction, or network-level access to exploit, but it does require local access to the SPI interface (as indicated by the attack vector being 'Adjacent' in the CVSS vector). The CVSS 4.0 score of 5.3 reflects a medium severity, primarily due to the limited attack vector and the impact being a DoS rather than data compromise. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability affects embedded systems using Silicon Labs' OpenThread RCP, which is commonly deployed in IoT devices and wireless mesh network applications that rely on Thread protocol for low-power, secure, and reliable device communication. The failure to clear the SPI buffer under high traffic can degrade network reliability and availability, potentially impacting critical IoT infrastructure that depends on continuous operation.

For European organizations, the impact of CVE-2025-2329 can be significant in sectors relying on IoT and wireless mesh networks, such as smart cities, industrial automation, healthcare, and building management systems. The denial of service caused by the RCP reset can lead to temporary loss of connectivity or control over critical devices, disrupting operations and potentially causing safety or compliance issues. Since the vulnerability affects the communication between the RCP and its host via SPI, devices that integrate Silicon Labs OpenThread RCP modules are at risk of intermittent failures or outages under high network traffic conditions. This can degrade service quality and reliability, especially in environments with dense IoT deployments. Although the vulnerability does not allow for data exfiltration or privilege escalation, the availability impact can indirectly affect confidentiality and integrity if fallback mechanisms or manual interventions are required. European organizations with deployments in smart infrastructure or industrial IoT should be aware of this risk, as it could affect operational continuity and increase maintenance overhead.

To mitigate the risk posed by CVE-2025-2329, European organizations should: 1) Monitor Silicon Labs' official channels for patches or firmware updates addressing this vulnerability and apply them promptly once available. 2) Implement network segmentation and traffic shaping to limit high traffic bursts that could trigger the SPI buffer corruption, thereby reducing the likelihood of the DoS condition. 3) Employ robust monitoring of device health and SPI communication errors to detect early signs of RCP resets or communication failures. 4) Where possible, design fallback or redundancy mechanisms in IoT deployments to maintain service continuity if an RCP reset occurs. 5) Engage with device vendors to confirm whether their products incorporate the affected OpenThread versions and request updated firmware or mitigation guidance. 6) Consider isolating critical IoT devices from untrusted or high-traffic environments to minimize exposure. 7) Conduct thorough testing of IoT device behavior under simulated high traffic to identify potential instability before deployment. These steps go beyond generic advice by focusing on traffic management, monitoring, vendor engagement, and architectural resilience specific to the nature of this vulnerability.