run bash script from php exec() - php

how to run bash script from php with sudo
index.php :
<?php
$arg;
exec("sudo /var/www/script", $arg);
?>
script :
!#/bin/bash
echo YOUR ARG IS $1;
sudoers www-data ALL=NOPASSWD /var/www/my
chmod 755 /var/www/my

Firstly, you can't sudo it directly like that. So you have to change some configurations in sudoers file.
Run sudo visudo in console, add the following line at the end of file
nobody ALL = NOPASSWD: /var/www/script
P.S.: It's a security risk to use your script like that which would sometime perform breach in data security in a great extent so my suggestion is don't call your script like that.

Related

How to make PHP execute Python3 script as root?

I want PHP to execute a Python3 script.
I have done
$command = escapeshellcmd('pathtofile.py');
$output = shell_exec($command);
echo $output;
But whenever the script is run, I get an error :Permission Denied.
I'm running a web server (Apache2 on Ubuntu 18.04) and the VPS has only one user- root.
I have also donechmod +x path.py and added the shebang line in the scipt.
Basically, the script is run when a user successfully registers.
You must to add apache user in sudoers file like:
www-data ALL=(ALL:ALL) NOPASSWD:ALL
then you can execute script like this:
'sudo pathtofile.py'
Or you can use compiled wrapper.
Write C program, that executes script, than compile it. Than set sticky bit:
chown root:root wrapper
chmod a+rs wrapper
Than include www-data in the root group.
Now can execute wrapper from your php script, and wrapper will execute python script as root.

shell_exec() not executing shell script

I've a shell_test.php file in /var/www/html folder with this code:
<?php
shell_exec('/var/www/html/config.sh');
?>
config.sh in the same folder has this code:
#!/bin/sh
sudo -u root kill -SIGHUP $(cat /var/www/html/mosquitto/mosquitto.pid)
When I run ./config.sh from folder, it runs.
When I run command in config.sh file directly in terminal, it
works too.
I've added this into sudoers file so that there is no need of password:
www-data ALL=(ALL) NOPASSWD: /var/www/html/config.sh
The thing is it's working fine when run using terminal in both the mentioned ways. Why is not executing when run in PHP?
Your problem is probably, that it is apache, www-data or some other user that is running your script and you try to run it as root.
Try without sudo -u root and change the group of the file to www-data with:
chown root:www-data your-script
As you say "It isn't outputting anything but my mosquitto broker is resetting every time it runs which lets me know"
I think you should replace
shell_exec('/var/www/html/config.sh');
with
$output = shell_exec('/var/www/html/config.sh');
echo $output;
According to php docs "shell_exec — Execute command via shell and return the complete output as a string"
shell_exec doesn't print by default; you have to store the string output and then use it
I made few changes in codes and it worked.
In shell_test.php, I changed code like this:
<?php
shell_exec('sudo -S ./config.sh');
?>
In config.sh, I changed like this:
#!/bin/sh
sudo kill -SIGHUP $(cat /var/www/html/mosquitto/mosquitto.pid)

Execute Python script from Php

I have a PHP webpage on my raspberry pi with 2 buttons (on and off)
The on button button redirects to On.php
The off button redirects to Off.php
In "/usr/lib/cgi-bin" I have a python script that I would like to execute (script.py)
I can perfectly execute it from the terminal by typing
cd /usr/lib/cgi-bin
sudo python script.py
It works if I do it from the terminal.
The problem is the PHP file (On.php) in my "/var/www" folder.
This is what I wrote:
<?php
exec('cd /usr/lib/cgi-bin');
exec('sudo python script.py');
?>
Why is the script executing from the terminal, but not from my PHP?
You can't use sudo from a PHP script. Apache is running from an user (www-data generaly), so edit this file : /etc/sudoers
Then add this line :
www-data ALL=(ALL) NOPASSWD:ALL
Care ! this will authorize all functions to be called by a PHP script, you can adapt changing "ALL" by your script or Python command.
Then precise your user in your exec command :
<?php
exec('sudo -u www-data python /usr/lib/cgi-bin/script.py')
Try this out, it should be working:
<?php
system("cd /usr/lib/cgi-bin");
system("sudo python script.py");
?>
Or even this:
<?php
system("cd /usr/lib/cgi-bin && sudo python script.py");
?>
On an older Raspbian distribution you need to place your file in /var/www/file.py. So in your file.php you add:
{
exec("sudo python /var/www/file.py");
}
On a newer Raspbian Jessie you need to place your file in /var/www/html/file.py, so in your file.php you need to add:
{
exec("sudo python /var/www/html/file.py");
}
Or just any file.py
<?php
{
exec("sudo python test.py");
}
?>
Note: For this to work you need to edit a file first to add these lines to allow passwordless sudo
sudo nano /etc/sudoers
then go to the bottom and add this
pi ALL=(ALL) NOPASSWD: ALL<br>
www-data ALL=(ALL) NOPASSWD: ALL

How to execute a shell script in PHP?

I have a script in /var/www/myscript.sh which creates folders and runs the command svn update for my projects. I need to execute this script by calling it in a PHP file in the browser (i.e. Localhost/test.php). I tried using functions shell_exec() and exec() but those did not work. I ran my shell script in terminal with su www-data && ./myscript.sh and it worked. What else am I missing?
<?php
$output = shell_exec("./myscript.sh");
?>
Update 5/4/2011:
I added www-data ALL=(ALL) NOPASSWD:ALL to /etc/sudoers and it works, but this is very insecure. Is there another way to do this?
Several possibilities:
You have safe mode enabled. That way, only exec() is working, and then only on executables in safe_mode_exec_dir
exec and shell_exec are disabled in php.ini
The path to the executable is wrong. If the script is in the same directory as the php file, try exec(dirname(__FILE__) . '/myscript.sh');
You might have disabled the exec privileges, most of the LAMP packages have those disabled. Check your php.ini for this line:
disable_functions = exec
And remove the exec, shell_exec entries if there are there.
Good Luck!
Residuum did provide a correct answer to how you should get shell exec to find your script, but in regards to security, there are a couple of points.
I would imagine you don't want your shell script to be in your web root, as it would be visible to anyone with web access to your server.
I would recommend moving the shell script to outside of the webroot
<?php
$tempFolder = '/tmp';
$webRootFolder = '/var/www';
$scriptName = 'myscript.sh';
$moveCommand = "mv $webRootFolder/$scriptName $tempFolder/$scriptName";
$output = shell_exec($moveCommand);
?>
In regards to the:
i added www-data ALL=(ALL) NOPASSWD:ALL to /etc/sudoers works
You can modify this to only cover the specific commands in your script which require sudo. Otherwise, if none of the commands in your sh script require sudo to execute, you don't need to do this at all anyway.
Try running the script as the apache user (use the su command to switch to the apache user) and if you are not prompted for sudo or given permission denied, etc, it'll be fine.
ie:
sudo su apache (or www-data)
cd /var/www
sh ./myscript
Also... what brought me here was that I wanted to run a multi line shell script using commands that are dynamically generated. I wanted all of my commands to run in the same shell, which won't happen using multiple calls to shell_exec(). The answer to that one is to do it like Jenkins - create your dynamically generated multi line of commands, put it in a variable, save it to a file in a temp folder, execute that file (using shell_exec in() php as Jenkins is Java), then do whatever you want with the output, and delete the temp file
... voila
If you are having a small script that you need to run (I simply needed to copy a file), I found it much easier to call the commands on the PHP script by calling
exec("sudo cp /tmp/testfile1 /var/www/html/testfile2");
and enabling such transaction by editing (or rather adding) a permitting line to the sudoers by first calling sudo visudo and adding the following line to the very end of it
www-data ALL=(ALL) NOPASSWD:/bin/cp /tmp/testfile1 /var/www/html/testfile2
All I wanted to do was to copy a file and I have been having problems with doing so because of the root password problem, and as you mentioned I did NOT want to expose the system to have no password for all root transactions.

sudo in php exec()

I don't know what the deal is here…
So I want to run an applescript: sudo osascript myscript.scpt
This works fine in the terminal, but not when I execute it via PHP's exec(); nothing happens. The console says
no tty present and no askpass program specified ; TTY=unknown ; …
I did my research, and it seems I'm missing the password for the sudo command. I tried a couple different ways to get around this, including:
writing %admin ALL=(ALL) ALL in /etc/sudoers
and proc_open() instead of exec()
none of which seem to be working, consequently driving me CrAzY!
So basically, is there a clear-cut way to get PHP to execute a simple terminal command?
EDIT: to clarify, myscript.scpt is a simple appleScript that changes the onscreen UI (for a larger project). In theory, simply osascript myscript.scpt should be enough, however the sudo is for some reason necessary to invoke some response from the system. If the sudo could be somehow eliminated, I don't think I would be having this permissions problem.
It sounds like you need to set up passwordless sudo. Try:
%admin ALL=(ALL) NOPASSWD: osascript myscript.scpt
Also comment out the following line (in /etc/sudoers via visudo), if it is there:
Defaults requiretty
I think you can bring specific access to user and command with visudo something like this:
nobody ALL = NOPASSWD: /path/to/osascript myscript.scpt
and with php:
#exec("sudo /path/to/osascript myscript.scpt ");
supposing nobody user is running apache.
php: the bash console is created, and it executes 1st script, which call sudo to the second one, see below:
$dev = $_GET['device'];
$cmd = '/bin/bash /home/www/start.bash '.$dev;
echo $cmd;
shell_exec($cmd);
/home/www/start.bash
#!/bin/bash
/usr/bin/sudo /home/www/myMount.bash $1
myMount.bash:
#!/bin/bash
function error_exit
{
echo "Wrong parameter" 1>&2
exit 1
}
..........
oc, you want to run script from root level without root privileges, to do that create and modify the /etc/sudoers.d/mount file:
www-data ALL=(ALL:ALL) NOPASSWD:/home/www/myMount.bash
dont forget to chmod:
sudo chmod 0440 /etc/sudoers.d/mount
I recently published a project that allows PHP to obtain and interact with a real Bash shell. Get it here: https://github.com/merlinthemagic/MTS
The shell has a pty (pseudo terminal device, same as you would have in i.e. a ssh session), and you can get the shell as root if desired. Not sure you need root to execute your script, but given you mention sudo it is likely.
After downloading you would simply use the following code:
$shell = \MTS\Factories::getDevices()->getLocalHost()->getShell('bash', true);
$return1 = $shell->exeCmd('/path/to/osascript myscript.scpt');
Run sudo visudo command then set -%sudo ALL=(ALL:ALL) to %sudo ALL=(ALL:ALL) NOPASSWD: ALL it will work.
I had a similar situation trying to exec() a backend command and also getting no tty present and no askpass program specified in the web server error log. Original (bad) code:
$output = array();
$return_var = 0;
exec('sudo my_command', $output, $return_var);
A bash wrapper solved this issue, such as:
$output = array();
$return_var = 0;
exec('sudo bash -c "my_command"', $output, $return_var);
Not sure if this will work in every case. Also, be sure to apply the appropriate quoting/escaping rules on my_command portion.
The best secure method is to use the crontab. ie Save all your commands in a database say, mysql table and create a cronjob to read these mysql entreis and execute via exec() or shell_exec(). Please read this link for more detailed information.
killProcess.php
I think directly calling a sudo command might be difficult because you are setting up the whole server to work without a password.
Perhaps as an alternative you could setup a CRONjob as root and monitor a flag file. Once the flag file exists it will run the osascript myscript.scpt and then delete the flag file.
This way you will keep SUDO secure from a config point of view and the server safer. To run the script you just need to touch the flag file from PHP.
It would of course introduce a delay of however many minutes you running the CRON job. It would also mean that you would have to redirect the output to a file and have a async monitor of the output, but it will depend on your application if this is a problem or not.
But it is an alternative that might protect the server.

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