Users cannot login

[Sayian]

Just today, i got about 80 emails from my site users saying they couldnt login.

When they login, it displays their user menu, where they can edit their profile, upload photos, ect ect.

They are saying they dont see the menu anymore, and they see hello guest, which is displayed if a session is not set.

Funny thing is ... i havent changed ANYTHING at all in over a month .. and i can login just fine.

But 80 users in 1 day not being able to login ... somthing is wrong?

Does anyone have any possible clue what could of made this happen?

[justsomeone]

Do you manage the server yourself? Could someone else have altered any of the server software, eg upgrading versions of PHP?

You can log in, but others can't. Are you logging in via the same infrastructure? Are you coming at this from a machine on the same LAN as the server, or are you coming through the sae internet connection as everyone else?

Otherwise, what's your application-level logging like? Does your authentication/login stuff write to a logfile? Are there any clues in there?

Are your passwords encrypted? Do you have backups? Is it possible to compare password fields with those from last week? This might lead you to considering some sort of a malicious attack.