将命令传递到使用bash脚本运行Shell的Binary中

Question

New to bash scripting so having a little teething problem and was wondering if someone could clear up some trouble I'm having, I have a simple C file called test that creates a shell as seen below:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int main()
{
  execl("/bin/sh", "/bin/sh", (void *) NULL);
  perror("exec");
 return 1;
}

I want to create a bash script to execute this file which I have done below, but then on execution I then wish to send commands to the shell that the binary creates - is this possible I am trying the following to no avail:

#!bin/bash
/var/testfolder/test; # execute the test c file to spawn the shell
??? #don't know how to pass commands to the new shell created :(

Answer 1

Your compiled C binary has the SETUID permission i suppose? With the binary and arguments you can execute any shell like this with this binary permission:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int main( int argc, char ** argv )
{
    execv("/bin/sh", argv );
    perror("exec");
    return 1;
}

Output of a test script to print arguments and current process:

$ ./test_execv ./test.sh foo bar
Executing $0: ./test.sh
Args $*: foo bar
process:
  PID TTY          TIME CMD
 3300 pts/1    00:00:08 bash
 3498 pts/1    00:00:00 sh
 3499 pts/1    00:00:00 ps

Security issue
If you can execute a script to a root shell, anyone can do this. I think you just have to add some of your scripts (only those needed) with a sudo permission to be run as root from your the needed account.

Answer 2

Try this:

#!/bin/bash
/var/testfolder/test <<EOF
cmdtopass1
cmdtopass2
cmdtopass3
EOF