mitm6 doesn't work on VPN tunnel interface. "mitm6 -i tun0 -d <domain name>"

[shawnsong]

   valid_lft forever preferred_lft forever

3: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 100
link/none
inet 10.10.15.169/23 brd 10.10.15.255 scope global tun0
valid_lft forever preferred_lft forever
inet6 dead:beef:2::11a7/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::e4e0:7a25:ea5d:b6ee/64 scope link stable-privacy
valid_lft forever preferred_lft forever

root@kali:/opt/mitm6# mitm6 -i tun0
Traceback (most recent call last):
File "/usr/local/bin/mitm6", line 8, in
sys.exit(main())
File "/usr/local/lib/python3.8/dist-packages/mitm6/mitm6.py", line 340, in main
config = Config(args)
File "/usr/local/lib/python3.8/dist-packages/mitm6/mitm6.py", line 57, in init
self.macaddr = netifaces.ifaddresses(self.default_if)[netifaces.AF_LINK][0]['addr']
KeyError: 17

[korang]

SAme issue with CSCOTUN0 cisco anyconnect vpn connection.

[InitRoot]

This is due to VPN on layer2 usually doesn't receive MAC addresses.
You can try modifying the code as below for line 57:

  if args.mac is None:
            self.macaddr = '00:00:00:00:00:00'
        else:
            self.macaddr = args.mac