CakePHP 2.2 AclExtras aco_sync in browser (sh permission denied) - cakephp

Question

I'm working on a remote server and I can't use the console because ssh is not enabled. So I need to run aco_sync directly from the browser (or any other way that doesn't involve the shell).
I managed to sync acos on my local dev server with the following code in controller/action:
$command = ROOT . DS . APP_DIR . DS . 'Console' . DS . 'cake';
$params = ' -app ' . ROOT . DS . APP_DIR;
$params .= ' AclExtras.AclExtras';
$params .= ' aco_sync';
$result = shell_exec($command . $params);
But on the production server (with cPanel) I just get no response for about 5 minutes and then I get an internal server error (500). I simply hangs. Actually, this happened on two different VPS servers with cPanel. In the first one, I had ssh and was able to run the command from the console. But when running the quoted code from the browser, I hung just as the other server.
I found no logged errors either on php log files nor cake's log files.
The action is prefixed with "admin_" and ACL doesn't allow execution if not logged in.
'./cake' script file has execute permissions (took me a while to figure this was necessary).
I tried on Chrome and IE8.
Debug level was set to 1.
After trying to run the script, the page broke and I wasn't able to browse until I opened an incognito window or restarted the browser.
I think the server's memory gets completely consumed when I run this script. I've had to restart httpd to get the site up and running again on the server that I could control.
I've seen some implementations using $dispatcher->dispatch() and tried a bunch of them but with no luck.
Any ideas?

Answer 1

App::uses('ShellDispatcher', 'Console');
$command = '-app '.APP.' AclExtras.AclExtras aco_sync';
$args = explode(' ', $command);
$dispatcher = new ShellDispatcher($args, false);
if($dispatcher->dispatch()) {
echo 'OK';
} else {
echo 'Error';
}

Answer 2

Try this, the $dispatcher->dispatch(); seems to show something only in case of an error.
run this and check your database.
App::uses('ShellDispatcher', 'Console');
$command = '-app '.APP.' AclExtras.AclExtras aco_sync';
$args = explode(' ', $command);
$dispatcher = new ShellDispatcher($args, false);
try {
$dispatcher->dispatch();
} catch (Exception $e) {
pr($e);
}