without this abort we get the following error on a non existing host:

msf  auxiliary(dlink_dir_300_600_exec_noauth) > run

[*] 192.168.178.1:80 - Sending remote command: cat /var/passwd
[-] 192.168.178.1:80 - Failed to connect to the web server
[-] Auxiliary failed: NoMethodError undefined method `body' for nil:NilClass
[-] Call stack:
[-]   /root/.msf4/modules/auxiliary/dlink_dir_300_600_exec_noauth.rb:66:in `run'
[*] Auxiliary module execution completed