What version are you running?
3.0.14
What's the URL of the page containing the problem?
login
What steps will reproduce the problem?

Remove the FQDN from ALLOW_HOSTS
Restart apache
Login


What is the expected output? What do you see instead?
For the emailed traceback to remove/redact the password
What operating system are you using? What browser?
not relevant 
Please provide any additional information below.
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/Django-1.6.11-py2.7.egg/django/core/handlers/base.py", line 180, in get_response

    response = callback(request, **param_dict)
File "/usr/local/lib/python2.7/dist-packages/Django-1.6.11-py2.7.egg/django/utils/decorators.py", line 95, in _wrapped_view

    result = middleware.process_view(request, view_func, args, kwargs)
File "/usr/local/lib/python2.7/dist-packages/Django-1.6.11-py2.7.egg/django/middleware/csrf.py", line 156, in process_view

    good_referer = 'https://%s/' % request.get_host()
File "/usr/local/lib/python2.7/dist-packages/Django-1.6.11-py2.7.egg/django/http/request.py", line 75, in get_host

    raise DisallowedHost(msg)
DisallowedHost: Invalid HTTP_HOST header: 'reviewboard-upgrade.sonos.com'.You may need to add u'reviewboard-upgrade.sonos.com' to ALLOWED_HOSTS.

<WSGIRequest

path:/reviews/account/login/,

GET:<QueryDict: {}>,

POST:<QueryDict: {u'username': [u'MY USERNAME'], u'csrfmiddlewaretoken': [u'AXfbdwZaxGdfzVfe5HPcVq5gl0Ycs8r0'], u'password': [u'!!!!!MY PASSWORD!!!!!'], u'next': [u'']}>,