Net Exec

Helper to start a local server and start a process on connection with I/O binded to the socket.

$ ./net_exec.py -p 12312 ./hello a b c

From another terminal:

$ nc localhost 12312
Your name: foo
Hello  foo  from  ['./hello', 'a', 'b', 'c']

To debug with gdb, run gdb -x gdbinit. It set the config required to follow the child fork and break when the new process start. When a process is catched, the listening python script is paused. Wait for the process to terminate and then use the resume macro to resume the script.

$ gdb -x gdbinit
(gdb) run ./net_exec.py ./hello a b c
... Open a connection with nc localhost 31337 ...

Catchpoint 1 (exec'd /usr/bin/python3.3), 0x00007ffff7ddd270 in _start ()
   from /lib64/ld-linux-x86-64.so.2
... You are now in the debugged process, set breakpoint as needed ...
(gdb) continue

[Inferior 3 (process 3280) exited normally]
(gdb) resume
... You can now open a new connection with nc localhost 31337 ...

Shellcode Compiler

Helper to compile and extract shellcode

Install pyelftools:

$ pip install pyelftools

Build shellcode:

$ ./shellcode_compiler.py hello.S
\xeb\x191\xc01\xdb1\xd21\xc9\xb0\x04\xb3\x01Y\xb2\x05\xcd\x801\xc0\xb0\x011\xdb\xcd\x80\xe8\xe2\xff\xff\xffhello