How to use auth_cookie_malformed action in WordPress

auth_cookie_malformed action

Fires if an authentication cookie is malformed.

To use auth_cookie_malformed action, first you have to register it using add_action. You can write this code into functions.php of your activated theme or in a custom WordPress Plugin.

We at WePlugins always prefer to create a custom WordPress Plugin while using hooks so nothing breaks when you update your WordPress Theme in the future.

In the below live example, we have defined a function weplugins_execute_on_auth_cookie_malformed_event which takes 2 parameters and we registered using add_action. The first parameter auth_cookie_malformed is the name of the hook, The second parameter weplugins_execute_on_auth_cookie_malformed_event is the name of the function which needs to be called, the third parameter is the priority of calling the hook if the same hook is used multiple times and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometimes, you have to remove a registered hook so you can use remove_action to remove auth_cookie_malformed action.

Parameters

Below are the 2 parameters required to use this hook.

• $cookie : (string) Malformed auth cookie.
• $scheme : (string) Authentication scheme. Values include ‘auth’, ‘secure_auth’, or ‘logged_in’.

Live Example

Below is an example of how you can use this hook.

    function weplugins_execute_on_auth_cookie_malformed_event($cookie, $scheme){
        // You can write code here to be executed when this action occurs in WordPress.
        // Use the parameters received in the function arguments & implement the required additional custom functionality according to your website requirements.
    }
    // add the action
    add_action( "auth_cookie_malformed", "weplugins_execute_on_auth_cookie_malformed_event" , 10, 2);
    

Example 1: Logging the malformed cookie

This example demonstrates how to log the malformed auth cookie for debugging purposes.

    function weplugins_log_malformed_cookie($cookie, $scheme){
        error_log("Malformed auth cookie detected: " . $cookie . " with scheme: " . $scheme);
    }
    add_action( "auth_cookie_malformed", "weplugins_log_malformed_cookie", 10, 2);
    

Example 2: Notify Admin via Email

This example shows how to notify the admin via email when a malformed auth cookie is detected.

    function weplugins_notify_admin_malformed_cookie($cookie, $scheme){
        $admin_email = get_option('admin_email');
        wp_mail($admin_email, "Malformed Auth Cookie Detected", "A malformed auth cookie was detected.nCookie: $cookienScheme: $scheme");
    }
    add_action( "auth_cookie_malformed", "weplugins_notify_admin_malformed_cookie", 10, 2);
    

Example 3: Redirect User to Login Page

This example redirects the user to the login page if a malformed auth cookie is detected.

    function weplugins_redirect_on_malformed_cookie($cookie, $scheme){
        wp_redirect(wp_login_url());
        exit;
    }
    add_action( "auth_cookie_malformed", "weplugins_redirect_on_malformed_cookie", 10, 2);
    

To remove a hook callback, use the example below.

    remove_action( "auth_cookie_malformed", "weplugins_execute_on_auth_cookie_malformed_event", 10, 2 );
    

Please make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

Contact Us

If you’re having any trouble using this hook, please contact our WordPress Development Team and we’d be happy to assist you.