The TELNET module tests accounts against the TELNET service. This module supports both telnet (23) and telnets (992).
The module currently has a single option, MODE. MODE can either be NORMAL (default) or AS400. The AS400 mode supports basic AS/400 tn5250 connections. This approach allows for more descriptive error messages than FTP when testing against an AS/400. However, POP3, if available on the AS/400, is still a better brute-force option.
The Telnet module will output to the log file hosts that were found to only have
a password prompt. This may be useful when scanning for use, or lack of, AAA.
Medusa Documentation