Non-RFC Compliant Telnet Traffic on Port 23

[agilessk]

Can someone explain about the threat name/vulnerability Non-RFC compliant Telnet traffic on Port 23?  

[OtakarKlier · Accepted solution]

Hello,

So to start telnet uses port 23. What the message is saying is that it see's the packets but it doesnt conform to the RFC, i.e. the packet doesnt look like its supposed to. Could be that the application sending the traffic is not forming the packets correctly, or another application other than telnet is using that port.

Hope that helps.

[agilessk]

Thanks for the response. how to investigate that the application sending the traffic is not forming the packets correctly or non-rfc compliant? any examples or references. Thanks again. 

[reaper · Accepted solution]

You can enable advanced packetcapture on the threat profile

That will allow you to verify what the firewall is receiving