Fixed Redirect Loop caused by 2FA login edge-case

[Steffen]

Affected version

2.2.16 and 2.3.0 RC4

How to reproduce:

1. Enable 2FA in your XenForo account if not already done
2. Log out from XenForo
3. Open https://xenforo.com/community/register/
4. Click on the "Log in" button in the header (this makes the login dialog appear on the register page whose URL remains the same)
5. Log in with your username + password
6. Complete the 2FA challenge

What happens next is an infinite redirect loop from https://xenforo.com/community/register/ to https://xenforo.com/community/login/two-step?_xfRedirect=https%3A%2F%2Fxenforo.com%2Fcommunity%2Fregister%2F&remember=1 and back again. Depending on your browser and server it will probably be terminated at some point by an "ERR_TOO_MANY_REDIRECTS" browser error, an "HTTP 429 Too Many Requests" server error or something similar.

 

[XF Bug Bot]

Thank you for reporting this issue, it has now been resolved. We are aiming to include any changes that have been made in a future XF release (2.3.0 RC 5).

Change log:

Avoid redirect loop when logging in from the registration page

There may be a delay before changes are rolled out to the XenForo Community.