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Gmail Accounts Vulnerable to XSS Exploit

Posted by michael on Fri Oct 29, 2004 04:27 PM
from the ooooooops dept.
mallumax writes "A security hole in GMail has been found (an XSS vulnerability) which allows access to user accounts without authentication. What makes the exploit worse is the fact that changing passwords doesn't help. The full details of the exploit haven't been disclosed. The vulnerability was reported by Israeli news site Nana. They were tipped off by an Israeli hacker. Google has been notified and they are working to close the hole. The Register has the story here."
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  • Oh no! (Score:5, Funny)

    by scaaven (783465) on Friday October 29 2004, @04:28PM (#10667702)
    My google stock. My poor google stock!
  • just a bit irresponsible to be coming out with this before Google has had a chance to fix it?
    • Re:Isn't it... (Score:5, Insightful)

      by realdpk (116490) on Friday October 29 2004, @04:31PM (#10667732) Homepage Journal
      No. Certainly not. People should be made aware of security issues. Especially for free services like this, where people have no guarantee they will ever be addressed.
      • Re:Isn't it... (Score:4, Insightful)

        by LiquidCoooled (634315) on Friday October 29 2004, @04:33PM (#10667760) Homepage Journal
        Its not like a local exploit where we can stop using it, or update ourselves.

        This SHOULD get maximum exposure. Maybe then the heads in google will jump on this with all their PHDs.

        As for not fixing it, I doubt thats an option. Such a monumental failure so start in their public offering will be devistating to them.
        • I should clarify that apart from deleting all my mail and closing my account I can do nothing about it. I don't want to lose my account though, I *like* gmail, and certainly don't want to go back to the hotmail wasteground.

          (and also look sheepishly at the grammatical screwup in my previous post)
    • by moonbender (547943) <moonbenderNO@SPAMgmail.com> on Friday October 29 2004, @04:33PM (#10667755)
      I guess they weren't kidding when they said it's still in beta...
        • Re:Isn't it... (Score:5, Interesting)

          Actually, those aren't the primary reasons. A Google app can be perfectly stable, and still be in beta, because "beta" for Google means looking for a way to make money off of it.

          Now, I don't have a problem with that at all. Also, I do agree that in this case, Google has GMail in beta for other reasons too (maybe not even the making money off it part - AdWords has been adapted to GMail, so they might already be making money off of it).
    • Re:Isn't it... (Score:4, Informative)

      by DaHat (247651) on Friday October 29 2004, @04:34PM (#10667764) Homepage
      Some might agree... others would say that if that was the case, Microsoft (and others) would never fix security holes if they are not known.
      • Re:Isn't it... (Score:2, Informative)

        Some might agree... others would say that if that was the case, Microsoft (and others) would never fix security holes if they are not known.

        Yes - but the key is that you should give the company in question enough time to be able to get a fix out before releasing the issue to the public. I haven't been able to RTFA however unless Google have not taken any action after a reasonable timeframe (say a week) posting the issue on slashdot is not going to solve the problem any faster, and hence is just making
    • Re:Isn't it... (Score:5, Insightful)

      by lukewarmfusion (726141) on Friday October 29 2004, @04:35PM (#10667775) Homepage Journal
      Yes and no.

      Yes - Google should have the opportunity to fix this appropriately, not racing against the slew of hackers, crackers, and script kiddies that want to exploit it.

      No - People should aware of security risks in the software, hardware, etc. that they use and upon which they rely.

      Personally, I prefer to inform the company of vulnerabilities and offer to help fix them. It's helped me land clients and discredit competitors.
        • Re:Isn't it... (Score:5, Interesting)

          by lukewarmfusion (726141) on Friday October 29 2004, @06:33PM (#10668768) Homepage Journal
          I did see an XSS proof-of-concept exploit (maybe yours) where the hacker imitated a Google page asking the user to pay for Google use. It was quite convincing.

          In that case, the exploit had been known for a long time. In the interest of protecting the not-so-savvy (read: gullible) users, publicity may get the attention needed for them to do their jobs. Giving them a reasonable chance to respond with their fix. Two years is way more than reasonable.

          To play devil's advocate, I'd say that it's not your responsibility to make sure their site is secure. If they want to leave it there, they can - and publicizing it is simply going to hurt those users that you'd seek to protect. It'll end up hurting Google in the end anyway.

          Personally, I prefer to do a "good deed" and help make the web a little safer for people like my wife's grandparents.
  • by LostCluster (625375) * on Friday October 29 2004, @04:29PM (#10667713) Homepage
    The articles reveal that the basic design of the bug is to snatch the victim's cookie, and then the hacker can use that cookie to get into the account forever more. That cookie will always lead to the victim's account no matter what... even if they log out, even if they change their password, the cookie will still be valid authentication.

    The XSS part is just an example of a way to steal the user's cookie. Clearly, any other way you can think of to grab a cookie file would work just as well.

    It's a surprisingly bad design by Google standards. By assigning an forever-good cookie value each users account, it eliminates the need to re-login at home after using GMail at a public terminal, but the problem is if that cookie value ever falls into enemy hands the account is compromised and cannot be re-secured. Re-assigning the cookie value at each logon is the more traditional way of securing such things, although that means users who hop between more than one computer or even browser would have re-authenticate every time they changed.
    • by ArbitraryConstant (763964) on Friday October 29 2004, @04:31PM (#10667733) Homepage
      I don't believe they use a forever cookie, they use a cookie that's invalidated after you log out OR (optionally) a 2 week cookie.

      What I don't like about it is that it doesn't use SSL after you log in.
      • by LostCluster (625375) * on Friday October 29 2004, @04:34PM (#10667767) Homepage
        The cookie file gets invalidated... but the problem is if you log back in, instead of getting a new value in your new cookie, apparently you get the same old value again. And worse yet, even if you don't log in again, bringing back that old cookie from the dead is all that's needed to log in.

        It's not the experation date on the cookie that's the problem, it's the fact that their database still assocates "your cookie" with your account even if there's no authorized cookie in circulation.
      • by kinema (630983) on Friday October 29 2004, @04:45PM (#10667864)
        What I don't like about it is that it doesn't use SSL after you log in.
        Actaully if you enter "https://gmail.google.com/gmail" in the location bar of your favorite browser you will continue to use a SSL secured connetion after for the duration of your session.
      • What I don't like about it is that it doesn't use SSL after you log in.

        ...which is important, because I want to read my mail over an encrypted link even though it travelled through several ISPs' data centers, many networks, a backbone or two, and probably even the FBI's scanners, IN THE CLEAR!!!

        • My immediate concern is the fskers who live in my apartment complex. We use a shared internet connection (300 of us on a dual T-1, ouch) for the entire complex. Now, I can't be the only person who knows that an un-administered network (no kidding) will be rife with people screwing around.

          I know that my email travels through routers and ISPs in the clear, but they probably don't know me personally. I'm more worried about my roommates sniffing the traffic coming from my computer to the gateway and reading
  • Oh my god! (Score:5, Funny)

    by Zangief (461457) on Friday October 29 2004, @04:29PM (#10667715) Homepage Journal
    Maybe some hacker will make a program to break into every gmail account, read their mail, and send them ads about what people are talking about in mails!!!
  • Cross site scripting should not be considered a vulnerability.
    • by Sheetrock (152993) on Friday October 29 2004, @04:38PM (#10667805) Homepage Journal
      Well, the problem is that we're looking at each individual XSS exploit as a vulnerability when we should be looking at XSS itself as an unwholesome feature in general.

      Like when we started treating e-mail as a file transfer protocol, or when documents began to contain executable content, XSS gives an avenue of attack by adding a new and unrequested behavior to something that used to be secure. We need to reduce these channels of exploitation if computers are going to become secure -- especially as we head towards a homogenized environment on the Internet with regards to executable code (.NET/Java).

      • by phasm42 (588479) on Friday October 29 2004, @04:46PM (#10667875)
        XSS is not the real problem here. The real problem is that the cookie can be used to authenticate an account. If you get a copy of the cookie and take it to another machine, you could log on using that cookie, even after the cookie has expired. This is a poor design, and XSS is just one way to exploit this. Another would be to simply copy Mozilla's cookies.txt file, or whatever browser you use. Or to sniff out the cookie over the network and use it from then on.
  • by yahyamf (751776) * on Friday October 29 2004, @04:32PM (#10667744)
    I waited so long to get a Gmail account, I don't care if it sucks now... I also like Doom3...
  • So isn't the real issue that there are bugs that allow your cookie file to be exposed? Shouldn't those be considered critical security bugs regardless of what Google does?
  • The first person to fix the exploit will get a FREE GMAIL INVITE!
  • Other bugs?? (Score:4, Interesting)

    by Anonymous Coward on Friday October 29 2004, @04:35PM (#10667779)
    Did anybody else notice when they were coming up with unique login names when they first set up their gmail account that oftentimes the "Blahblah@gmail.com is taken" message would often be some other email address somebody else was trying? I mean, if you tried "johndoe@gmail.com" and it was taken, sometimes it would respond with "joeschmoe1234@gmail.com is already taken, try again".
  • by whovian (107062) on Friday October 29 2004, @04:37PM (#10667793)
    Never heard of XSS until now (like me)? Here is one summary one summary [cgisecurity.com] of what the cookie theft looks like.
  • The Nana article says that it works by stealing your cookies, so I don't think the problem should last longer than two weeks, since that's how long the Gmail cookies are supposed to be good for.

    I've been using the Gmail account for stuff I could afford to lose, since there doesn't seem to be any way to shift it in bulk to my home computer. Now I'm really glad I didn't use it for anything important.

  • by Dominic_Mazzoni (125164) on Friday October 29 2004, @04:40PM (#10667818) Homepage
    I may be misinterpreting the story, but it sounds to me like you need more than just the username: you need to actually trick the user into giving you their GMail cookie by phishing. Obviously, this is a huge security hole and Google should fix it immediately, but it's not quite the same as the Hotmail backdoor from last year, which didn't require phishing at all. As long as you don't ever click on a link that sends you to GMail from an untrusted source, you should be safe.
    • by poot_rootbeer (188613) on Friday October 29 2004, @05:41PM (#10668373)
      you need to actually trick the user into giving you their GMail cookie by phishing. ...or by grabbing the cookies left behind by previous users off a public terminal.

      But that's a minor concern, no one ever uses a public computing terminal to check webmail, or walks away without logging out properly.
  • by bill_kress (99356) on Friday October 29 2004, @04:44PM (#10667856)
    They caught this problem in beta, just as should be done! Bravo!

    Brings some true professionalisim to an industry where companies actually ship/sell products with bugs like this all the time.
  • Easy Fix: (Score:5, Insightful)

    by thesandtiger (819476) on Friday October 29 2004, @04:50PM (#10667915)

    1) Gmail plugs the hole.

    2) They change the cookie validation test script in this case to require a different cookie than ones that were being given while the exploit was active.

    3) When a counterfeit cookie (or any of the old cookies) tries to validate it's immediately seen as invalid, and the user is then made to login.

    Of course, if someone already got at your stuff, well, that's bad.

  • Wives (Score:5, Funny)

    by mekanizer (823259) on Friday October 29 2004, @04:55PM (#10667954)
    Time to read our wives e-mail to see if they are cheating or something.
  • by NotoriousQ (457789) on Friday October 29 2004, @05:06PM (#10668039) Homepage
    No worries! Remember it is still a beta. It is not like anyone will use this for a serious purpose.
  • by elmegil (12001) on Friday October 29 2004, @05:21PM (#10668183) Homepage Journal
    "Because Gmail offers a gigabyte of storage, several times bigger than most other web based mail services, users hardly delete any old correspondence", says Goldshlagger. "The result is a huge amount of mail accumulating in the users' boxes, which frequently include bank notices, passwords, private documents and other files the user wanted to backup. Who ever takes a hold of this data, could literally take over the victim's life and identity".

    If you've got ALL THAT INFORMATION already migrated to a BETA service that's been around for ... a handful of months, you're pretty foolish. As far as it goes, I specifically DON'T have anything particularly importang going to my gmail account for exactly this reason--it's unproven as of yet. In fact, I had a two week outage, totally unable to use my gmail box, for uknown reasons. After working with the GMail team, it got fixed, but they never told me the actual cause. Yet another reason not to trust BETA software/services with really crucial information.

    And before all the 'bots claim I'm bashing google, quite the contrary. I love GMail. But it's like any other BETA product right now--still working out the kinks.

  • Fixed Perhaps? (Score:4, Interesting)

    by mla_anderson (578539) on Friday October 29 2004, @06:39PM (#10668804) Homepage

    I wonder if they fixed it. My session was just expired and I had to login in again. (My latest two week session ended a couple days ago.)

  • I was using the "don't ask my password for two weeks" feature - Gmail just logged me out although the two weeks aren't up, and after logging in again I had a session ID tacked on to the URL like this:

    http://gmail.google.com/gmail?_sgh=2f3ab242adinf in itum

    which I've never seen before.

    I think it'll be a long Friday night at the 'Plex.
  • by nonicenamesleft (826555) on Friday October 29 2004, @08:55PM (#10669460)
    I know this group loves to hate Microsoft, but this story rings a bell in my head about the argument Microsoft always gives about its vulnerabilities being discovered the most cos hackers are more interested in finding them. With google having acquired a close to God status with its amazingly engineered products, those same hackers are now targetting its holes (pun intended).

    This story talks about this vulnerability in google which allows somone to replace the google page with a simple form telling the user that google is now a subscription service and asking for their credit card details. http://www.theregister.co.uk/2004/10/21/google_des ktop_security_vuln/ [theregister.co.uk]

    Is closed-source software always going to be insecure because some hacker somewhere has issues with it? I hope not - cos writing closed source software is my bread and butter.

    With google's empire growing the way it is, I wonder if it is the next Microsoft? I sincerely hope not!

    • As the reporter of the first bug reported in the register article, I certainly didn't go looking for it because of google, it was trivial to find, I found it 2 1/2 years ago (you can see a usenet post from 2002 which describes it, when XSS into google didn't matter much, phishing was new, and google had no data)

      The reason we're getting this deluge of security flaws in google now is simply because people are now looking, they're easy to find, the XSS flaws are trivial (like ignoring you're encode user input
    • Account security problems should be worked out long before public beta status. Beta should be reserved for functionality, GUI, and interoperability issues.

      I wonder how many people are using this 'beta'?

      • Re:it IS a beta... (Score:5, Informative)

        by RetroGeek (206522) on Friday October 29 2004, @05:12PM (#10668083) Homepage
        Beta should be reserved for functionality, GUI, and interoperability issues.

        No that is alpha. Once all the functionality is complete, the GUI has been approved, and the application can talk to the other applications it needs to, THEN the product goes into beta testing.

        Beta is there to locate any bugs which made it past the alpha testers. Beta apps are considered feature complete.
    • Re:it IS a beta... (Score:5, Insightful)

      by buzzini (177741) on Friday October 29 2004, @04:46PM (#10667878)
      Labeling something "beta" almost indefinitely should not be a get-out-of-jail-free card. It seems to me that once a product is in fairly widespread use -- once a product has a marketing plan behind it -- saying "no fair, it's a beta!" is a little disingenuous.

      • Labeling something "beta" almost indefinitely should not be a get-out-of-jail-free card. It seems to me that once a product is in fairly widespread use -- once a product has a marketing plan behind it -- saying "no fair, it's a beta!" is a little disingenuous.

        Agreed, maybe Google is laurel resting in the wake of the IPO.

        Do you remember web searching prior-Google? I used to take pride in knowing the Hotbot and AltaVista switches (and nand not) but Google's 1998 blew all that away. That level of knowl
      • Re:it IS a beta... (Score:5, Insightful)

        by WIAKywbfatw (307557) on Friday October 29 2004, @05:44PM (#10668401) Journal
        Care to explain what marketing plan for Gmail you've seen? So far, Google has issued a couple of press releases - announcing its intention to offer email services, etc - but nothing more than that, and it's made it repeatedly clear that the service is in beta.

        Have you ever seen more than that? Have you seen any advertising (banner or otherwise) for the service? Just how do you contend that Google is marketing it?

        And how the hell are you defining "fairly widespread use"? Just how many Gmail accounts do you think there are? 100,000? A million? Well, in comparison, how many Microsoft Hotmail or Yahoo Mail accounts do you think there are out there? I'd be surprised if Gmail had even a hundredth of the user base that its key competitors possess.

        Gmail is in beta. Until they say it's not in beta please accept that nothing should be taken for granted. And the fact is that even "shipped" products aren't error free, so either learn to accept that things sometimes go wrong with software or just stop using a PC altogether.
      • Re:it IS a beta... (Score:5, Informative)

        by QuantumFTL (197300) * <<justin.wick> <at> <gmail.com>> on Friday October 29 2004, @05:50PM (#10668455) Homepage
        Labeling something "beta" almost indefinitely should not be a get-out-of-jail-free card. It seems to me that once a product is in fairly widespread use -- once a product has a marketing plan behind it -- saying "no fair, it's a beta!" is a little disingenuous.

        I highly disagree. When I use a product which is in "Beta" I do not expect it to meet the same level of stability/security etc. To do so is rediculous - anyone who develops software should understand why products of this kind require an extended beta period. It's definitely the best time to make last minute changes, adjustments, and to find problems like this. Finding these problems is the whole point of it being Beta in the first place. Anyone who's using this service for anything important, and then complaining about problems they have (other than as normal beta feedback) is being unreasonable!

        From their Terms of Use [google.com]:
        you understand and agree that the Service is provided on an AS IS and AS AVAILABLE basis.
        Their terms of service are very short, and easy to understand (not like most software agreements) and use of gmail is not only FREE, but it's entirely optional. No one's making you use it. People should not have the same level of expectation for this new service as they do of the original search engine, and if they, that's their own ignorance.

        I also highly doubt that this beta period will last that much longer. GMail is becoming popular enough that the bugs and changes should be done soon.

        Cheers,
        Justin
    • by iMaple (769378) on Friday October 29 2004, @05:07PM (#10668042)
      what's the difference if a few Hackers get a hold of your account?

      You know its not just as simple as you think. I mean I dont care if a few hackers read my email, but what if they decide to use sensitive info in it or delete it.

      I run an e-business from Nigeria and earn some money in the process. People email me their bank account numbers, creditcard numbers ,SSNs and what not (I am creative). Now if some immoral hacker got hold of that data , the poor users would be duped twice, and I would feel really bad abt it (I mean I could have got twice the money myself if I wanted). So I request Gmail to help the Nigerian revolution and our fight against AIDS and dictators and fix the bug as soon as possible.
        • by bheer (633842) <rbheer.gmail@com> on Friday October 29 2004, @05:49PM (#10668448)
          > Cookies compromise privacy in the same way,

          No. Cookies are not the same across sites. Since each site comes up with its own cookie encoding scheme, data sharing becomes difficult (barring schemes like Passport: one reason why Passport in its original form was so creepy). Today, with fine-grained cookie managers (Moz, Opera) you can browse the web pretty privately, at least wrt cookies.

          Incidentally, Real once got a lot of flak for incorporating just this feature into Realplayer, all the privacy arguments made then are true now as well.

          Classic cookies are supposed to be opaque keys, but in reality people do use them for storing nonsensitive information, like stylesheet info. Your proposal would increase the hassle these people have to go through.

          > but also can give the client state control if not used properly

          rm if not used properly can hose your $HOME. A backup script used by a technician at your ISP used improperly can hose your Maildir. Doesn't mean rm or backup scripts are bad.

          Btw, if you don't like client-side state, I suggest you get prepared for more unpleasantness: I'm predicting in 2-3 years we'll see the first browsers with more sophisticated client state management that'd allow browsers to work with websites (even app-centric websites like Gmail and Flickr) offline.