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Microsoft Tries To Censor Bing Vulnerability
An anonymous reader writes "Microsoft's Bing search engine has a vulnerability with its cash-back promotion, which impacts both merchants and customers. In traditional Microsoft fashion, the company has responded to the author of the breaking Bing cash-back exploit with a cease & desist letter, rather than by fixing the underlying security problem. It is possible for a malicious user to create fake Bing cash-back requests, resulting in not only fake cash-back costs for the merchant, but also blocking legitimate customers from receiving their cash-back from Bing. The original post is currently available in Bing's cache, although perhaps not for long. But no worries, the author makes it clear that the exploit should be painfully obvious to anyone who reads the Bing cash-back SDK."
it will probably be all over the rest of the internet and general common knowledge within the week.
A bullet may have your name on it but splash damage is addressed "To whom it may concern."
I'm curious how 'anonymous reader' knows that Microsoft is doing nothing to fix the problem. This has been bugging me for a long time. Its possible that a workable solution could take some time to get implemented, and in that time, doesn't it make sense to send a C&D letter in the interim? Hell, doesn't it make sense to send the letter anyways, so you don't have all these assholes trying to break your system? A C&D letter doesn't mean that other actions haven't been taken. Just a thought.
It seems like people have still not learned to never trust anything from the user. This reminds me of some trivially exploitable web merchants years ago. The would store the entire shopping basket, including prices, in the user's cookies. User simply modifies their cookies so that everything costs $1 or $0.01 and they could order a dozen cpus / t-shirts / whatever for a few bucks.
is the line from the letter
"cease and desist the posting in any location of the material and information contained in this post"
Seeing as it is their SDK that contains the details of this "feature", are they going to send themselves a C&D and then pull the SDK?
Regarding the tracking pixel approach: H.L. Mencken once wrote, "there is always a well-known solution to every human problem -- neat, plausible, and wrong." I cannot think of a situation to which this sentiment better applies.
After about 30 years is this still news?
Use Microsoft software and you get screwed. They don't design software they design the user interface and botch the software. They are now as always a marketing not an IT company. It's always been that way, it will always be that way.
If anyone is quickly wondering exactly where he got the info to construct the request URL in his original post (like, how did he know about jftid, jfoid, and jfmid?), it looks like page 33 of the linked Integration Guide PDF gives the URL https://ssl.bing.com/cashback/javascripts/1x1tracking.js. That JavaScript file has info on constructing that URL.
If you have a glaring vulnerability that lets people defraud your customers out of arbitrary amounts of money, the only sane thing to do is immediately disable the feature. Not wait for a solution. Not cover up the issue. You make coverage of the issue irrelevant. If one person figured it out and wrote about it, 100 other people also figured it out and are using it for personal gain.
Don't think of it as a flame---it's more like an argument that does 3d6 fire damage
All Microsoft needed to do was include a Message Authentication Code (such as, say, HMAC-SHA1) in the tracking image URL. Microsoft and the merchant obviously already have a shared secret they can use for the purpose. Using a MAC would have been practically free.
Given what Microsoft pays its programmers, I'm just appalled that nobody thought to include basic precautions in a brand-new interface written in this day and age. Whoever wrote the Bing API specification really should have known better.
http://lkcl.net/reports/bing.censorship.attempt - additional mirrors will be added as i find them.
This is no more a cheat than taking someone's money for a shell game and showing them afterwards how they were scammed.
If he's said "by the way, I managed to get 20 grand off you by this" then he's not defrauded them. If he'd kept quiet THEN he'd have defrauded them.
This is called "fraud". Look it up. It's been around for a long time, a lot longer than HTTP. There are standard business practices for dealing with it. Not all of them are technical. This system's technical defenses are probably sufficient to raise an alarm (delayed by a few weeks as the results are collated), and it will produce a pretty good paper trail leading to the owner of the Bing account. Some of the systems take into account minor details such as the existence of accountants, a police force, a paper trail, and a legal system. Obviously some stronger technical measures might have made it a bit more difficult to pull off this partucular fraud, or maybe it might have even stopped it, but the non-technical measures will also work just fine if they are called into play.
Whether or not the door is obviously guarded, it's still illegal to steal stuff from a store. The fact that the door was not protected with the latest and greatest in RFID theft detection systems doesn't change the fact that what you are doing is illegal. And perhaps the tracking process is slower than what you see in movies, people still get tracked down and arrested, days or weeks after the event. Moving from the streets onto the Internet doesn't really change the rules much (except that your case will probably wind up with Federal jurisdiction).
In this case, the poor "hacker" (I wish him/her luck!) appears to have done the following:
1. Used a specially formatted HTTP request to get a small fabricated purchase to show up as credited to his/her Bing account.
2. Noticed that the cash back did show up with no problem as "available for withdrawal".
3. Tried again with a much larger purchase. Again the purchase shows up in his account.
4. Hacker is hoping that the amount will soon become available for withdrawal.
On the other side of the world, the accounting systems for Microsoft and the associated merchant have likely compared invoices and noticed the discrepancies. The small ones got noted, but they were thrown out as "somebody is playing with the system, but it's not worth dealing with it". But this month, when going over the books, they're going to find a nice big 100,000 item that doesn't match up with any purchase recorded on the store's official records. However, they do have the account number of the buyer that should be getting the cash back. I'm not sure what typically happens at this point, but it probably involves cancelling dinner for the wolf pack so that by the time they're ready to send out the posse, the wolves are hungry.
In this case, Microsoft has apparently (I haven't looked into this) provided an API by which a store can report a sale and attribute the sale to a particular Bing account. The API has varying levels of security, depending on how much effort the store wants to put into preventing fake transactions from entering the system. Low effort might be fine and takes less time to set up, but it's easier to attack and that means more work to do when reconciling the accounts. Just like many other mechanisms for quickly distributing non-critical information between merchants, this isn't meant to be the authoritative information transmission system, just a way for people to keep status on accounts in between the regularly-scheduled account reconciliations. This way Bing can update your account balance within seconds of the purchase. Of course, the payback won't happen until they've gone back and checked Microsoft's records against the merchant's records and pulled out any differences. The differences go to the auditor and possibly to the police or FBI.
Could we maybe just think for a second before acting like jerks? Being a jerk means everybody suffers. I mean, just because I see a way to deface somebody's website doesn't mean I am obligated to do so. I walk by 100 cars a day, and I could easily spray shaving cream all over them and not get caught. But if everybody did that, quality of life would go down for everybody. Same thing on the internet.
I hate this attitude out there th
Time flies like an arrow. Fruit flies like a banana.
Your car has an exploit, so I stole it and drove it into a wall to prove a point.
This is my sig.
Microsoft has posted this page in response:
http://www.bing.com/search?q=bing+cashback+vulnerability&go=&form=QBLH&filt=all&qs=n
You know, there is a difference between trolling and pointing out the flaws in your reasoning. Just saying.