CVE-2025-6693 is a critical memory corruption vulnerability identified in RT-Thread, an open-source real-time operating system (RTOS) widely used in embedded systems and IoT devices. The flaw affects versions up to 5.1.0, specifically within the device driver core component (components/drivers/core/device.c). The vulnerability arises from improper handling in several key device interface functions: sys_device_open, sys_device_read, sys_device_control, sys_device_init, sys_device_close, and sys_device_write. These functions are responsible for managing device lifecycle and I/O operations. An attacker with local access can exploit this vulnerability by manipulating these functions to trigger memory corruption, potentially leading to arbitrary code execution, privilege escalation, or system instability. The attack vector is local, requiring at least low privileges (PR:L) but no user interaction (UI:N) is needed. The vulnerability has a CVSS 4.0 base score of 8.5 (high severity), reflecting high impact on confidentiality, integrity, and availability (VC:H, VI:H, VA:H). The vendor has not responded to disclosure attempts, and no patches or known exploits in the wild are currently reported. Given RT-Thread’s role in embedded and IoT environments, exploitation could compromise critical device functions or enable persistent footholds in industrial, consumer, or infrastructure devices.

For European organizations, the impact of CVE-2025-6693 is significant, especially for sectors relying on embedded systems and IoT devices running RT-Thread. These include industrial automation, smart manufacturing, automotive systems, telecommunications infrastructure, and smart city deployments. Exploitation could lead to unauthorized control over devices, disruption of critical services, leakage of sensitive operational data, or use of compromised devices as pivot points for broader network intrusion. The local attack requirement limits remote exploitation but insider threats, compromised local access, or malware with local execution capabilities could leverage this vulnerability. Given the increasing integration of embedded devices in European critical infrastructure and industrial environments, successful exploitation risks operational downtime, safety hazards, and regulatory non-compliance under frameworks like NIS2 and GDPR if data confidentiality is breached.

1. Immediate mitigation involves isolating and restricting local access to devices running vulnerable RT-Thread versions, minimizing the risk of local exploitation. 2. Implement strict access controls and monitoring on embedded devices to detect anomalous usage of device interface functions. 3. Employ network segmentation to limit lateral movement from compromised devices. 4. Since no official patch is available, organizations should consider applying temporary code-level mitigations such as input validation and bounds checking in the affected functions if source code access and expertise permit. 5. Engage with RT-Thread community or vendors for updates or unofficial patches. 6. Conduct thorough inventory and risk assessment of all RT-Thread-based devices in the environment to prioritize remediation. 7. Enhance endpoint detection and response capabilities to identify exploitation attempts targeting embedded devices. 8. Plan for firmware updates or device replacement where patching is not feasible.