In total, 11 stacks were analyzed: uIP, FNET, picoTCP, Nut/Net, lwIP, cycloneTCP, uC/TCP-IP, MPLAB Net, TI-NDKTCPIP, Nanostack, and Nucleus NET. Millions of devices, including everything from IT file servers to IoT embedded components, use uIP, FNET, picoTCP and Nut/Net. Researchers found improperly generated ISNs in nine of the 11 stacks analyzed. Researchers said they disclosed the vulnerabilities to the affected vendors and maintainers in October 2020. “Most vendors have already issued patches and/or mitigation recommendations to users. The developers of Nut/Net are working on a solution, and Forescout has not received a response from the uIP developers,” the report added.