I'm running Magento latest version on Nexcess server.
I have created custom module to store template design in database. I'm using PHP code within textarea like,
<div> First Name: <?php echo $order->getFirstname?></div>
I'm using form Post method. When trying to save data It's throwing 403 Forbidden error. However when i'm adding same content to the CMS Block, CMS Page and transactional emails, it's working fine.
Note: I have changed all file permission to 644 and folder permission to 755 except var (777) and media (777).
Apache mod_security extension is enabled on server. But why different behaviour between CMS page and my custom module.