If you get a message similar to the following when accessing your WordPress site's control panel:
The requested URI could not be accessed.
Or, for older versions of PHP:
Warning: Unknown: failed to open stream: Permission denied in Unknown on line 0
Warning: Unknown: failed to open stream: Permission denied in Unknown on line 0
Fatal error: Unknown: Failed opening required '.../wp-login.php' (include_path='...') in Unknown on line 0
this indicates that your WordPress login page has been temporarily disabled to protect your site, your wallet (and us, other sites we host, and the Internet at large) from a hostile attacker trying to force their way into your site.
When this happened, an email was sent to you with the full details, including how to resolve the situation. You should have that email. If you don't, stop and make sure your member contact email address is up to date and that your email system is not marking messages from us as spam.
When you next need to log in to your WordPress site, all you need to do is reset the permissions of your wp-login.php script. The recommended permissions for this script are 0644. This is typically done with a command like:
YourPrompt$ chmod 644 /home/public/wp-login.php
(If your blog is not installed in /home/public, you may have to adjust this.)
You can run this command from the shell or using the "Run Shell Command" action on the Site Information panel for this site in our member interface. Just edit the permissions of the wp-login.php file and make sure that it is readable by everyone.
If you have frequent problems with this, you may wish to investigate the security options presented in the "Stopping Login Attacks" and "General Security" sections of our Advanced WordPress Configuration guide.