A few days ago I got a call from someone that asked for my help.
He said that he can not login into the management section of some site that he is using,
he said that he talked to the technical personal on that site and they said that the problem is not on their side and he also said that he can use his user name and password to login to that site from another machine.
The symptoms on his machine where such that after he entered his username and password he would be sent back to the login page. so I played with it for some time.
I looked for browser hijacking and odd network activity and found none. Eventually I found that if he does not check the "remember me" option he can login and there is no problem.
So I left him sort of happy that he can now use the said system.
The day after I got another call from him saying that now he can not login even to his Google account. I looked at the problem and the browser (IE) was saying that there was a network problem. ping to google works and telnet to port 80 also gave the expected results... Switched over to Google chrome and got a better error message: Redirect loop...
hmmm.... google to the rescue.
It turns out that the date on this machine was set to about 3 months in the future, causing any cookie that was set to a future time (based on the server time of course) to expire immediately.
I reset his machine's date and voila, everything was working.
so next time google does not work for you, make a note of the date and time.
Eyal