We have a problem whereby an unknown update a couple of weeks ago meant that Firefox, Chrome, Safari and Internet Explorer can no longer access a certain website.

At the moment, only my netbook which hasn't been on-line seems to have escaped.

I've loaded the exact same versions of Firefox and Java onto an old PC that my netbook has in order to try and get a machine we can use, but it still refuses. So it's seemingly not a Java or Firefox update.

The site relies heavily on Cookies to do the login, which is the part that fails. I know there are new cookie laws, but I can't think how that could be applied except via specific browser updates.

Can anyone think what the update might have been? It was incredibly pervasive with not a single machine I've tested in dozens of separate locations having escaped it, despite some supposedly having all updates disabled.

try the host file and see if its listed there ...

Thanks Steve.

I'm accessing it by IP address so the host file isn't really relevant. It's not listed anyhow.

then the only thing i can think of, as its system wide, on all browsers is DNS or firewall blocking ...

Do your sites use the same IP address JJ? At my work, due to the size of the organisation and the low number of IP addresses we use some websites have blocked us; I wonder if something similar is happening to you?

The webpage is the admin login for a piece of hardware. It has a LAN address. We have about a thousand of these in the field, and every customer we've checked can no longer login.

The firmware has not been updated in any case, so it's not the boxes that have changed.

The manufacturer denies all knowledge, although they have released an update that fixes it. The first update in over a year...

The problem is that only my Netbook is able to access any of these devices. All browsers successfully bring up the login page, but the login fails on any PC that's been updated in the last two weeks regardless of browser.

My first thought was that it was a Java update, but that doesn't seem to be the case. There's no Java applets involved and I've tried old versions anyway with no success.

I do feel it's most likely cookie related because that's how the login operates, but the question is what kind of update happened two weeks ago that changed cookie behaviour on every PC I've seen? It seemingly broke Firefox on Ubuntu and IE9 on Windows 7. I don't have access to a Mac to check that - although it may never have worked in some scenarios.

OK turns out the version I was running on my Netbook was irrelevant. The relevant fact was that the date was wrong!

It's a Y2K style bug...

On what?

On the code that checks the cookie to see if the login was valid. Nothing to do with browsers or Java or Windows updates or anything else I'd been looking at....

Wow.

And that hit in 2012 because....

I can't see the actual code so I don't know exactly, but just guess at bad maths with little foresight.
Actually I think I might be able to SSH in and get a better look. Might be good for a laugh when I get a free minute! I should probably have tried that before...