Users logged in to other accounts

[Hooligan]

Had to close my board because users are being logged in as other random users. What the heck? I asked my server people and they didn't help at all. :/ I don't know what's going on or how to fix it.

 

[teletubbi]

I saw this with other forum software occasionally also.
With the other software it was related to some issues with cache.

But the wrong logged in users wasn't able to access conversations as example.

Clearing the cache did the trick there.

 

[Hooligan]

Unfortunately I did that, and it was a no go. In fact, the issue has gotten worse. Users were able to see PMs and make posts as other users.

 

[delicatebobster]

have you been messing with ssl since this happened?

 

[Hooligan]

No, I haven't touched anything except the caches. Do you have a suggestion?

 

[delicatebobster]

no suggestions here sorry

 

[Hooligan]

Thanks anyway. ^^

 

[whynot]

Unfortunately I did that, and it was a no go. In fact, the issue has gotten worse. Users were able to see PMs and make posts as other users.

Seems that's not an XF bug.
Disable all the addons.
Upgrade your board urgently with a fresh copy of XF.

 

[rdn]

Do you have LiteSpeed Full Page Cache or Nginx fastcgi_cache enabled?

 

[Paul B]

Whenever we have seen this before it has been due to server level caching.

https://xenforo.com/community/threads/possible-security-issue.112813/
https://xenforo.com/community/threads/major-users-logging-in-as-other-users.108043/
https://xenforo.com/community/threads/members-being-logged-in-as-different-members-on-1-4-4.113491/