https://www.bleepingcomputer.com/news/security/openwrt-sysupgrade-flaw-let-hackers-push-malicious-firmware-images/

A flaw in OpenWrt's Attended Sysupgrade feature used to build custom, on-demand firmware images could have allowed for the distribution of malicious firmware packages.

OpenWrt is a highly customizable, open-source, Linux-based operating system designed for embedded devices, particularly network devices like routers, access points, and other IoT hardware. The project is a popular alternative to a manufacturer's firmware as it offers numerous advanced features and supports routers from ASUS, Belkin, Buffalo, D-Link, Zyxel, and many more.