how to run a root process from php (not on CLI either)

sfullman

ok here is the deal, I need to read, from a browser, the contents of /var/spool/cron

Of course its permissions are set to be very unfriendly to PHP (running as a linux user account) to read that folder.

So, I tried making a file in /home called /home/readcrons.php, I added the hashbang at top and chown'd to root, and made it executable. The file itself is pretty simple and there is no security risk in the file.

Now, in php, I tried:

echo `/home/readcrons.php`;

It spit at me and said you don't have the permissions. I presume that even though the FILE is owned by root, it acts with the permissions of the user calling it, is this correct?

Is there ANY way I can make this work? There must be something built in that is simple and elegant..

Thanks,
Sam

proudfist

Hi,

Look into shell_exec, http://php.net/manual/en/function.shell-exec.php

# example
$crontab = shell_exec('crontab -l');

sneakyimp

a php script's permission to run other scripts is only as powerful as the user that initiated the script in the first place -- i.e., whichever script starts things rolling is the one whose permissions are inherited by all the subsequent scripts.

Now, I believe it is possible for a script to assume root permissions, but can mean you have to read the password from somewhere which basically means you need to store it in a file. As you can imagine, this is problematic for security reasons. If you can add a user to the wheel group or sudoers list, then it may be possible for that user to assume root permissions without supplying a password. I am sorry I don't have more specific details.