This module is not compatible with the Password Policy module (and possibly other modules that use drupal_goto inside of hook_user_login(). One way to experience a problem is to use that module's "Password Expiration Warning" setting. The resulting effect of this is that a user who has a password that about to expire will be redirected upon user_login, and will not be required to provide 2-factor auth. Duo.module gives itself a very high weight in the system table (4000), and any other modules redirecting the user during login will avoid triggering the Duo 2-factor login.
Why a weight of 4000? -4000 would make more sense (in this scenario).
Comments
Comment #1
Leeteq commentedRef. #2507409: Immediately logged out when using password reset form ..:
Comment #2
chousmith commentedI just ran in to this issue again today with Password Policy set to Expire Passwords after 90 days, admin-level user password was to expire within the next 7 days, which bypassed Duo 2-factor auth. Some 4 years after the issue was initially reported.
Drupal 7.59 + Duo v7.x-1.1 + Password Policy 7.x-1.15