The mqlink.elf is service component in Ruijie RG-EW300N with firmware ReyeeOS 1.300.1422 is vulnerable to Remote Code Execution via a modified MQTT broker message.
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.