156 lines
4.7 KiB
Python
156 lines
4.7 KiB
Python
#!/usr/bin/python
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#
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# Simple script showing configuration of the DTP protocol on
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# the switch's port. This reconessaince will be helpful for performing
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# VLAN Hopping attacks.
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#
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# Mariusz B. / mgeeky, '18
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#
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import os
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import sys
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from scapy.all import *
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config = {
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'count' : 10,
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'timeout' : 90
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}
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ciscoConfigMaps = {
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2: '''
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ACCESS/OFF/ACCESS
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Administrative Mode: static access
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Operational Mode: static access
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Administrative Trunking Encapsulation: dot1q
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Operational Trunking Encapsulation: native
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Negotiation of Trunking: Off''',
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3: '''
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ACCESS/DESIRABLE/ACCESS
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Administrative Mode: dynamic desirable
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Operational Mode: static access
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Administrative Trunking Encapsulation: dot1q
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Operational Trunking Encapsulation: native
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Negotiation of Trunking: On''',
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4: '''
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ACCESS/AUTO/ACCESS
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Administrative Mode: dynamic auto
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Operational Mode: static access
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Administrative Trunking Encapsulation: dot1q
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Operational Trunking Encapsulation: native
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Negotiation of Trunking: On''',
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0x81: '''
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TRUNK/ON/TRUNK
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Administrative Mode: trunk
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Operational Mode: trunk
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Administrative Trunking Encapsulation: dot1q
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Operational Trunking Encapsulation: dot1q
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Negotiation of Trunking: On''',
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}
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def showConfig(stat):
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if stat in ciscoConfigMaps.keys():
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print(ciscoConfigMaps[stat])
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def inspectPacket(dtp):
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tlvs = dtp['DTP'].tlvlist
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stat = -1
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for tlv in tlvs:
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if tlv.type == 2:
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# TLV: DTPStatus
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stat = ord(tlv.status)
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break
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print(' ' + '=' * 60)
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if stat == -1:
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print('[!] Something went wrong: Got invalid DTP packet.')
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print(' ' + '=' * 60)
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return False
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elif stat == 2:
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print('[-] DTP disabled, Switchport in Access mode configuration')
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print('[-] VLAN Hopping via Switch Spoofing/trunking IS NOT possible.')
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print('\n\tSWITCH(config-if)# switchport mode access')
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elif stat == 3:
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print('[+] DTP enabled, Switchport in default configuration')
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print('[+] VLAN Hopping via Switch Spoofing/trunking IS POSSIBLE.')
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print('\n\tSWITCH(config-if)# switchport dynamic desirable (or none)')
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elif stat == 4 or stat == 0x84:
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print('[+] DTP enabled, Switchport in Dynamic Auto configuration')
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print('[+] VLAN Hopping via Switch Spoofing/trunking IS POSSIBLE.')
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print('\n\tSWITCH(config-if)# switchport mode dynamic auto')
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elif stat == 0x81:
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print('[+] DTP enabled, Switchport in Trunk configuration')
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print('[+] VLAN Hopping via Switch Spoofing/trunking IS POSSIBLE.')
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print('\n\tSWITCH(config-if)# switchport mode trunk')
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elif stat == 0xa5:
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print('[?] DTP enabled, Switchport in Trunk with 802.1Q encapsulation forced configuration')
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print('[?] VLAN Hopping via Switch Spoofing/trunking may be possible.')
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print('\n\tSWITCH(config-if)# switchport mode trunk 802.1Q')
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elif stat == 0x42:
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print('[?] DTP enabled, Switchport in Trunk with ISL encapsulation forced configuration')
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print('[?] VLAN Hopping via Switch Spoofing/trunking may be possible.')
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print('\n\tSWITCH(config-if)# switchport mode trunk ISL')
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showConfig(stat)
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print(' ' + '=' * 60)
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return True
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def packetCallback(pkt):
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print('[>] Packet: ' + pkt.summary())
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def main(argv):
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if os.getuid() != 0:
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print('[!] This program must be run as root.')
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return False
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load_contrib('dtp')
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print('[*] Sniffing for DTP frames (Max count: {}, Max timeout: {} seconds)...'.format(
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config['count'], config['timeout']
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))
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dtps = sniff(
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count = config['count'],
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filter = 'ether[20:2] == 0x2004',
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timeout = config['timeout'],
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prn = packetCallback,
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stop_filter = lambda x: x.haslayer(DTP)
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)
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if len(dtps) == 0:
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print('[-] It seems like there was no DTP frames transmitted.')
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print('[-] VLAN Hopping may not be possible (unless Switch is in Non-negotiate state):')
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print('\n\tSWITCH(config-if)# switchport nonnegotiate\t/ or / ')
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print('\tSWITCH(config-if)# switchport mode access')
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return False
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print('[*] Got {} DTP frames.\n'.format(
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len(dtps)
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))
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success = False
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for dtp in dtps:
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if dtp.haslayer(DTP):
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if inspectPacket(dtp):
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success = True
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break
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if not success:
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print('[-] Received possibly corrupted DTP frames! General failure.')
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print('')
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return success
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if __name__ == '__main__':
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main(sys.argv)
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