The SSH daemon on MikroTik routers through v6.44.3 could allow remote attackers to generate CPU activity, trigger refusal of new authorized connections, and cause a reboot via connect and write system calls, because of uncontrolled resource management.
https://www.exploit-db.com/exploits/48228
https://packetstormsecurity.com/files/156790/Microtik-SSH-Daemon-6.44.3-Denial-Of-Service.html