Vagelis,
First, this question is better suited for the security / firewalling forum (https://supportforums.cisco.com/community/5966/firewalling), but no worries.
Assuming the two networks are separated by the firewall, you will need to add a rule that allows telnet from 192.168.1.5 to 192.168.5.82.
If you want detail, you will need to post your config so we can give you the exact command to run. Be sure to remove sensitive information (public IP Addresses, SNMP Communities, pre-shared keys, passwords, etc.) before posting.
Regards,
Jeff