Slashdot Mirror
Google 302 Exploit Knocks Sites Out
clsc writes "The exploit: Redirect via 302 to another page of your choice, then watch as the URL of your redirect script replaces the URL of that carefully selected page in Google's search results. Once this happens, feel free to redirect any visitor that is not Googlebot to any other page of your choice. Also applies to other search engines as well (not Yahoo! though)."
Hey look! Someone forgot to RTFA!
You use 302 to hijack someone else's page in Google's search results. Your bogus ad infested page shows up instead of the actual content the user was searching for (and thought they were going to see), while the real website that you hijacked doesn't get any more Google traffic. That's the exploit.
Dumbass.
The main thread about this on WebMasterWorld is over 500 posts now.. lots of good info there.
This sig all sigs devours
There seems to be a lot of confusion as to why exactly this is such a big deal. A lot of people saying there's no problem or that this is nothing... basically just not understanding the issue. Let me explain:
Suppose you have a small business under the domain http://xyz.com/, and search engines bring you a lot of traffic because you rank high for keywords in your market. You have a lot of people out there linking to you, a lot of satisfied customers, good content on your site. You're always in the top 10 somewhere when people search for "xyz widgets".
Well, this issue with Google makes it very easy -- incredibly easy -- for someone to knock your site out of the rankings entirely. And I mean for *everything*, to where searching for your own company name in quotes literally buries you hundreds of pages deep in the results. We're talking sites going from getting 1000 unique hits to 10 overnight.
And here's the kicker: It requires absolutely no technical knowledge, no time investment, and is perfectly legal...
All I have to do is have another domain handy that is roughly as popular as yours. And I make a "links" page, like one of those directory services, that lists your website. But instead of being a normal hyperlink, it's a CGI (or PHP or ASP or whatever) script that generates a 302 redirect to your domain... Now, these are very simple, common scripts. One-liners that you can download from cgiscripts.com and stick on your server. The original intent of these scripts is to track which links are being clicked on your site. But now they've found a new use, because when Google gets that 302, all hell breaks loose.
See, according to the HTTP spec, 302 is a *temporary* redirect, which means Google is supposed to interpret whatever content it finds at the 302 target (your site) as really belonging to the URL of the source (my site). Google is just obeying the spec strictly here, and with devestating results. Why? BECAUSE THE DUPE FILTER NOW KICKS IN! You see, Google has a "dupe filter" that says if the same exact content is found for two unique URLs, then one of the URLs is obliterated in the rankings. Because after all, searchers don't want to be finding the same content over and over. If that happens, they'll start using a different search engine. But Google, sticking strictly to the HTTP spec, doesn't know who the content really belongs to when it gets a 302.
So Google essentially flips a coin. And if it comes up tails, say bye-bye to your domain in the rankings. Your *entire* domain. Because the dupe filter isn't limited to just the page that the 302 is pointing to -- it applies across your entire domain.
These 302 "exit-link-trackers" are all over the web. They've been used by webmasters for years. But it's just recently that Google has started treating 302 this way, so it didn't have any bad effect before. But now it kills you.
The funny thing is, the solution seems pretty simple: Just stop treating 302s this way if they point to a different domain. But for whatever reason Google isn't listening. Hopefully the press that's being generated now will give them the kick in the ass that they need.