CVE-2025-5869 is a critical memory corruption vulnerability identified in RT-Thread version 5.1.0, specifically within the sys_recvfrom function located in the rt-thread/components/lwp/lwp_syscall.c source file. RT-Thread is a widely used open-source real-time operating system (RTOS) designed for embedded systems and IoT devices. The vulnerability arises due to improper handling or manipulation of the 'from' argument passed to the sys_recvfrom function, which leads to memory corruption. This type of flaw can cause undefined behavior, including potential crashes, data corruption, or arbitrary code execution. The vulnerability has a CVSS 4.0 base score of 8.6, indicating a high severity level. The CVSS vector indicates that the attack vector is adjacent network (AV:A), requiring low attack complexity (AC:L), no user interaction (UI:N), and low privileges (PR:L). The impact metrics show high confidentiality, integrity, and availability impacts (VC:H, VI:H, VA:H), meaning exploitation could lead to significant compromise of the affected system. The vulnerability does not require user interaction and can be exploited remotely by an attacker with some level of local or adjacent network access but low privileges. No known exploits are currently reported in the wild, and no patches or vendor advisories are listed yet. Given RT-Thread's role in embedded and IoT environments, exploitation could allow attackers to execute arbitrary code or disrupt system operations, potentially affecting critical infrastructure or industrial control systems that rely on RT-Thread.

For European organizations, the impact of this vulnerability could be substantial, especially for those operating in sectors that rely heavily on embedded systems and IoT devices running RT-Thread, such as manufacturing, automotive, smart cities, healthcare, and critical infrastructure. Exploitation could lead to unauthorized control over devices, data breaches, disruption of services, and potential safety hazards if embedded systems control physical processes. The high impact on confidentiality, integrity, and availability means that sensitive data could be exposed or manipulated, and critical systems could be rendered inoperative. Given the increasing adoption of IoT and embedded technologies in Europe, this vulnerability poses a risk to operational continuity and data security. The requirement for low privileges and no user interaction lowers the barrier for attackers, increasing the likelihood of exploitation in environments where RT-Thread 5.1.0 is deployed without timely patching.

1. Immediate identification and inventory of all devices and systems running RT-Thread 5.1.0 within the organization to assess exposure. 2. Apply patches or updates as soon as they become available from RT-Thread maintainers or community sources. In the absence of official patches, consider upgrading to a later, unaffected version of RT-Thread. 3. Implement network segmentation and strict access controls to limit exposure of RT-Thread devices to trusted networks only, reducing the attack surface. 4. Monitor network traffic for unusual or suspicious activity targeting sys_recvfrom or related system calls, using intrusion detection systems tailored for embedded environments. 5. Employ runtime protections such as memory protection units (MPUs) or hardware-enforced security features available on embedded platforms to mitigate exploitation impact. 6. Conduct security audits and penetration testing focused on embedded devices to identify potential exploitation attempts. 7. Collaborate with device manufacturers and vendors to ensure timely security updates and vulnerability management for embedded systems.