Using the back button after logging out shows you pages from the authenticated user's session Using the back button after logging out shows you pages from the authenticated user's session.

I found a solution for this, need to set the header like this to fix this issue-

drupal_add_http_header('Cache-Control', 'no-cache, no-store, max-age=0, must-revalidate, post-check=0, pre-check=0');


But the problem where i need to set this header?
I set the header in index.php file. After that i am not able to see any other pages while i am logged in. (getting page not found error)

Any solution, how to fix this issue??
You can implement hook_init() in any of your custom modules

&lt;?php 
/**
* Implements hook_init().
*/
function YOUR_MODULE_NAME_init() {
     drupal_add_http_header('Cache-Control', 'no-cache, no-store, max-age=0, must-revalidate, post-check=0, pre-check=0');
}
?&gt;