An issue was discovered on GL.iNet devices before version 4.5.0. There is an NGINX authentication bypass via Lua string pattern matching. This affects A1300 4.4.6, AX1800 4.4.6, AXT1800 4.4.6, MT3000 4.4.6, MT2500 4.4.6, MT6000 4.5.0, MT1300 4.3.7, MT300N-V2 4.3.7, AR750S 4.3.7, AR750 4.3.7, AR300M 4.3.7, and B1300 4.3.7.
https://github.com/gl-inet/CVE-issues/blob/main/4.0.0/Authentication-bypass.md
http://packetstormsecurity.com/files/176708/GL.iNet-Unauthenticated-Remote-Command-Execution.html