Cursed User?!

[Kazhal]

Maybe someone has an idea:
I have a user in my forum who had problems logging in. After various attempts on his part, I have now reset his password via ACP. If I now try to log in with his account and the new password for testing, I only get a white page and the error "HTTP ERROR 500" after confirming the password. The page is then completely inaccessible, even after closing and reopening the browser. Only after deleting the browser data (cookies etc.) can I access the forum again. So far, the problem can only be reproduced with this account. In the ACP, he appears like any other user (although he is also assigned to the group of moderators, but there are others there too).

Thanks in advance, with best regards Peter

[Marc Stridgen]

I would suggest first of all checking your server error logs to see what the actual error is. If you are getting an internal server error, then this is where it would be logged.

Also, disable all 3rd party items and test the same

[balazsp]

@Kazhal modsecurity (if it is used) can do this if the username is any of the mysql commands or a substring of a known bad useragent string.

https://xkcd.com/327/

 

[Kazhal]

On 10/14/2022 at 9:16 PM, balazsp said:

@Kazhal modsecurity (if it is used) can do this if the username is any of the mysql commands or a substring of a known bad useragent string.

https://xkcd.com/327/

 

I don't use modsecurity, although the name is certainly not otherwise reserved in any way (="minischda"). Nevertheless thanks for the hint!

[Kazhal]

On 10/14/2022 at 5:47 PM, Marc Stridgen said:

I would suggest first of all checking your server error logs to see what the actual error is. If you are getting an internal server error, then this is where it would be logged.

Also, disable all 3rd party items and test the same

The tip definitely put me on the right track. Until recently, I was still running PHP 7.4 and the "MemberMap" app. After the recommendation in the ACP to finally switch to PHP 8.0, I did so. After that, however, the forum was initially blocked (access to the ACP, however, was still running). Eventually I found out that the "MemberMap" was the culprit. After I deactivated them, the forum ran again. So far so good.
As you pointed out, I checked the system logs. To my amazement, there were still reports about the "MemberMap". Then I tried to uninstall it. However, this also led to the same error message as when the user in question logged in. The solution was to first change PHP to 7.4, then uninstall the app and finally back to 8.0. However, why the problem only occurred with this one user and, as far as I know, with no other ... I have no idea.

Thank you for your hint!

[Marc Stridgen]

The only way you will know the answer to the last question there would be to ask the author of that application. Glad you know what was causing the problem.