This is a fix to a long outstanding remote code execution bug – post from Threatpost
Dennis Fisher discusses the basics of this issue
this is a bug from 2011 (sic) and could cause someone to access your older Cisco router
pax-pentest.com has a list of the telnet Metasploit payloads
Here are the relevant entries:
msf > use auxiliary/scanner/telnet/telnet_version
msf auxiliary(telnet_version) > set RHOSTS 192.168.1.103
RHOSTS => 192.168.1.103
msf auxiliary(telnet_version) > set RPORT 23
RPORT => 23
msf auxiliary(telnet_version) > run
I will update this post as I test the metasploit modules more.