Vulnerability affects GoAhead, a tiny web server created by Embedthis Software LLC, a company based in Seattle, USA. The tiny server is popular with hardware vendors since it can run on devices with limited resources, such as Internet of Things (IoT) devices, routers, printers, and other networking equipment. Attackers can exploit this flaw if CGI is enabled and if a CGI program is dynamically linked. The exact number of vulnerable devices is hard to determine as Shodan will return all GoAheads products, not just the vulnerable ones.
Source: https://www.bleepingcomputer.com/news/security/vulnerability-affects-hundreds-of-thousands-of-iot-devices/