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Security Mozilla The Internet

Hijacking Firefox Via Insecure Add-Ons 87

Posted by kdawson from the update-me-please dept.
An anonymous reader writes "Many makers of extensions or add-ons for Firefox are introducing ways for bad guys to hijack the Web browser, new research suggests. A great many add-ons are updated over insecure (non https://) connections, providing an avenue for attackers to replace the extension with an evil update. Google's add-ons are particularly vulnerable, because they update automatically without notifying the user. From the story: '[I]f an attacker were to hijack a public Wi-Fi hot spot at a coffeehouse or bookstore — a fairly trivial attack given the myriad free, point-and-click hacking tools available today — he could also intercept this update process and replace a Firefox add-on with a malicious one.'" Here is security researcher Chris Soghoian's description of the vulnerability and a video of a simulated takeover.
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Hijacking Firefox Via Insecure Add-Ons More

Hijacking Firefox Via Insecure Add-Ons

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  • fud? (Score:4, Interesting)

    by TinBromide ( 921574 ) on Thursday May 31, 2007 @07:48AM (#19335627)
    They mention the google plugin. Doesn't google offer almost all of its firefox offerings as IE search bars, desktop agents, and stuff like that. So why is the update structure for firefox different than, say, google search bar on IE?

    • Re: (Score:2, Informative)

      by Anonymous Coward
      You're right, but while FF is made to be extended with plugins, IE users rarely install addons (the most with at least on addon on IE I have seen was Google toolbar). That's why FF is a dangerous target than IE.

      The problem aabou the use of HTTP for updates is that mozilla.org takes weeks to update the release on their addon website (simpy plugin, for example, was affected by this: the 0.3 release took more than 2 weeks to appear on addons.mozilla.org). Otis, the simpy admin, told me about this while I wrote

      • Re:fud? (Score:4, Interesting)

        by mhall119 ( 1035984 ) on Thursday May 31, 2007 @08:17AM (#19335947) Homepage Journal
        Any developer can create their own SSL Certificates for free. It's getting a certificate that's been signed by a vendor already in Firefox's whitelist that they are paying for. I would rather each developer create their own self-signed certificate, then I get to decide who to trust, not Verisign.

        But using HTTPS wouldn't solve this problem either, because Verisign will sell a certificate to anyone with money. What should be happening is that developers sign their packages like they do for DEB and RPM package distros. That way you always know that you're getting your updates from the same person, no matter what your internet connection.

        • Re:fud? (Score:5, Insightful)

          by JesseMcDonald ( 536341 ) on Thursday May 31, 2007 @08:44AM (#19336317) Homepage

          Alternately, the Mozilla team could create their own signing certificate and add it to Firefox's whitelist; add-on developers could then get Mozilla-signed certificates for themselves. That would at least narrow the list a bit -- as you say, anyone can get a Verisign certificate, in part because there are just so many possible uses for one, but there should be few enough official Mozilla-signed add-on certificates to allow for some proper screening.

          The certificates could also be used for authentication of the updates themselves, as you suggested.

          • Re:fud? (Score:4, Informative)

            by Myen ( 734499 ) on Thursday May 31, 2007 @09:09AM (#19336709)
            Unfortunately, doing that would sort of imply Mozilla would need to vouch for the extension developers (hey, they're letting them use a cert; that's what it's for, right?). As it is they barely have enough people to just try installing extensions before approving for the main site...

            If it's just extension updates anyway, and extensions already act as a part of Firefox (i.e. they're not sandboxed... which they can't be in the current architecture)... They might as well just require SSL for updates, and people who don't use the Mozilla update service can just ship their own (self-signed) cert with the extension. Of course, some authors will still work around that by doing their own thing anyway. (There were, at one point, very, very insecure extensions that... load the whole toolbar at runtime using eval() by pulling data from unsecured sites.)

            • Unfortunately, doing that would sort of imply Mozilla would need to vouch for the extension developers (hey, they're letting them use a cert; that's what it's for, right?). As it is they barely have enough people to just try installing extensions before approving for the main site...

              I don't really see how this would be any more time- or reputation-intensive than granting accounts on the official Mozilla add-on site; it would simply be another step in the account-creation process. It might even help with

          • Re: (Score:2)

            by plover ( 150551 ) *
            I like this idea a lot, but who will "pay" for the service? Running a CA does cost money -- you've got to pay someone to answer the certificate requests, for example. And unless that CA is doing some kind of research on the submitters of the add-ons, the quality assurance is no different than what we get from Verisign's level 3.

            A certificate won't guarantee quality, it's just supposed to guarantee that we can hunt down the person to whom it was issued. Verisign doesn't offer that unless you get to thei

        • Re: (Score:3, Insightful)

          by itlurksbeneath ( 952654 )

          I would rather each developer create their own self-signed certificate, then I get to decide who to trust, not Verisign.

          You need to read up on what the ssl certs are for. They are not for trust, they are for verification. Any dork can create an ssl cert and say he's John "Maddog" Hall, but to get a VERIFIED certificate from a issuing agency saying you're indeed John "Maddog" Hall requires a LOT of verification of identity.

          If you choose to trust an un-verified cert, then you are right back in the same boat as TFA is talking about.

          • Then you need to read up on what VeriSign actually does. Someone with a VeriSign ssl cert hasn't verified who they are, they've only verified that they have (or more likely 'had') a credit card number and a small amount of money. I haven't tried it, but you can probably get one with a pre-paid Visa gift card.

            I would rather trust a cert verified by me, than one verified by VeriSign.
        • Let me get this straight: After years of open source software guys struggling with Verisign , self signed certificate paranoia creating alerts of Java and the horrible situation in Symbian which is just slowly getting fixed (except closed source)- Firefox developers opted in for the exact Windows scheme of doing things?

          I can't blame plugin developers, a self signed certificate alert really looks more evil than unsigned code.

          That Verisign/Symbian signed crap is _the_ reason why Commwarrior type of Symbian tr

    • Re:fud? (Score:5, Insightful)

      by DaveWick79 ( 939388 ) on Thursday May 31, 2007 @09:25AM (#19337005)
      The different is, everyone knows IE is insecure because of this. But everyone expects Firefox to be this totally secure, unhackable browser when it really isn't. The point is that the same things can be done on both browsers.

      Another point is how this affects the Google Gears project that was in a previous post. Now you have cross platform hackability for an application that could potentially host your critical apps.

      • Re: (Score:3, Interesting)

        by jedidiah ( 1196 )
        It's pretty easy to completely disable extensions. It won't "spoil your browser experience" either.

        That would be the big difference here between firefox and explorer.

        The real problem is when website authors make network dependencies with this kind of crap and scorn open standards. While many firefox extensions are nifty they are entirely optional. This is in stark contrast to the current trend in requiring flash or other plugins for every stupid little thing.

        Quicktime buttons are another fun one.

  • Don't trust public nets. (Score:5, Insightful)

    by Rob T Firefly ( 844560 ) on Thursday May 31, 2007 @07:49AM (#19335635) Homepage Journal

    [I]f an attacker were to hijack a public Wi-Fi hot spot at a coffeehouse or bookstore -- a fairly trivial attack given the myriad free, point-and-click hacking tools available today -- he could also intercept this update process and replace a Firefox add-on with a malicious one.
    This is why you shouldn't be performing anything as heavy as software updates over networks you don't totally trust, least of all the lash-ups in your average coffeehouse.

    • Re: (Score:2)

      by brunes69 ( 86786 )
      I think you need to RTFA, or event he summary, again. The Google toolbar updates automatically. So do a lot of other extensions.

    • This is why you shouldn't be performing anything as heavy as software updates over networks you don't totally trust...
      You mean, like the Internet?
  • I would think this is an issue with the specific ad-on, not really Firefox. I guess you could say Firefox should only allow https traffic...

  • No shit! (Score:1, Informative)

    by Anonymous Coward
    This is why extensions should all be signed or have the update servers SSL cert hard-coded.

    We can prevent attacks like this easily.
  • How about setting your updates (yes, even for add-ons) to NOT download automatically? That way you can at least control when they download...
  • ...and what happened to Google's "Do no evil" slogan?

    Then again these days Firefox itself pretty much forces you to update if you want to easily install extensions. What is with forcing people to download the plugins at install time? Last time I checked there was a plugin that allowed you to download to install later. That makes no sense. Why do I need a plugin to do this???

    I use to have a stable browser with 1.0. With 1.5 and 2.0 I often have to restart the thing if I open lots of tabs and some of the page

    • Re: (Score:1, Informative)

      by Anonymous Coward
      This has nothing to do with Firefox's built-in forced updates. The problem here is extensions you download from sites other than addons.mozilla.org, since they might include their own non-standard update methods which don't verify security certificates. Posting AC because I have to go to work and don't want to wait 10 minutes to reply.
    • You laughed at IE for being full of stuff nobody uses.

      You derided Opera's minuscule userbase.

      You vied for the top dog spot.


      Well, now you're on your way to getting there. You're gaining markt share. With growing market share come the demands of progressively dumber users - it's just the nature of the technology market. FF's code needs a good clean-up.

      • Re: (Score:2)

        by Dan Ost ( 415913 )
        With growing market share come the demands of progressively dumber users

        I've never heard it expressed so succinctly (and without cussing).

        Beautiful.

  • Addons from addons.mozilla.org not vulnerable (Score:5, Informative)

    by CTho9305 ( 264265 ) on Thursday May 31, 2007 @08:08AM (#19335845) Homepage
    The vast majority of the open source/hobbyist made Firefox extensions - those that are hosted at https://addons.mozilla.org/ [mozilla.org] - are not vulnerable to this attack. Users of popular Firefox extensions such as NoScript, Greasemonkey, and AdBlock Plus have nothing to worry about.

    Since it's not mentioned in the summary, it's important to reiterate that this takes advantage of non-secure update mechanisms used by some addons. The addons.mozilla.org site will only host extensions that update from addons.mozilla.org through the built-in mechanism, which is not vulnerable to this attack. This is an extension-specific issue, and would most likely apply to any sort of addon for any software that doesn't verify security certificates.

  • Maybe if you spent more time with your plug-in's they wouldn't feel that way. Have some compassion!

  • Is it viable? (Score:5, Insightful)

    by Xtense ( 1075847 ) <xtense@[ ]pl ['o2.' in gap]> on Thursday May 31, 2007 @08:13AM (#19335905) Homepage
    So ok, it is possible to do such an attack, but... is it viable enough as an attack vector? I mean, the attacker would have to sit 24/7 near an unsecure hotspot and/or an unsecure network to wait for a potential victim, and, as we know, firefox users aren't the majority, so this further narrows down the possibility of a successful attack. That's enough to call it improbable i think. Of course, since such an attack is possible, that can mean something, but, please, would anyone sit around coffee shops all day just to infect one person with spyware, when he could just, I dunno, send viruses or trojans through mail to computer illiterate people?
    • The person doesn't have to actually be there. You could disguise a server as a book on a bookshelf in a coffee shop and infect and collect all day.
      • And after "all day" was done, you still probably wouldn't have more than one victim. It would be more profitable and less work to pick pockets, if you're planning to do evil at a coffee shop.

        This topic is kind of like the Linux virus stories that appear every few months: it's just anti-free-software FUD.

  • Firefox extensions are insecure (Score:3, Interesting)

    by 140Mandak262Jamuna ( 970587 ) on Thursday May 31, 2007 @08:15AM (#19335925) Journal
    Right from day one I realized that the extensions provided by Firefox could become an security issue. I use very few of them. Scriptblock, Adblock and almost nothing else. And I disable auto updates. But on the other hand, Firefox is not so closely tied to the OS that they could take this breach, elevate privileges and take over a system, like ActiveX vulnerabilities.

    Yes, one should be careful about the extensions, and use them carefully. And one should be careful about using WiFi in coffee shops and hotels. I am far more worried about our salesmen plugging in their lap top in some hotel network in Bangkok, pick up an infection and coming to corporate HQ and plug that laptop in our intranet, behind the firewall, in the trusted network. I have asked my sysadmin to set up a separate network for laptops that might be used outside our intranet that is not part of the trusted intra net.

    • Re: (Score:3, Funny)

      by gardyloo ( 512791 )

      I am far more worried about our salesmen plugging in their lap top in some hotel network in Bangkok, pick up an infection and coming to corporate HQ and plug that laptop in our intranet, behind the firewall, in the trusted network.
      Wow. You kids these days and your descriptions of the clap!

    • I have asked my sysadmin to set up a separate network for laptops that might be used outside our intranet that is not part of the trusted intra net.
      Ask him to take a look on 802.1x http://standards.ieee.org/getieee802/download/802. 1X-2004.pdf [ieee.org]. You can give access to different VLAN based on software policies (i.e. having AV updated and so on)

      • Ask him to take a look on 802.1x http://standards.ieee.org/getieee802/download/802 [ieee.org]. 1X-2004.pdf. You can give access to different VLAN based on software policies (i.e. having AV updated and so on)

        You obviously confused some things:

        EEE 802.1X is an IEEE standard for port-based Network Access Control; it is part of the IEEE 802 (802.1) group of protocols. It provides authentication to devices attached to a LAN port, establishing a point-to-point connection or preventing access from that port if authentication fails.

        You might want to read the documents you refer to. I guess, what you meant was NAC - Network Admission Control [cisco.com]

    • Right from day one I realized that the extensions provided by Firefox could become an security issue.[...]

      OK, so it's about the "extensions provided by Firefox"? No, it's explicitly about extensions not provided by firefox but strapped on by some mechanism devised by the extension's developer, be it Google, Yahoo, whomever.

      Extensions provided by Firefox are downloaded via a secure connection - it's your Google-toolbar that comes unprotected.

      So, if you don't have a clue, read the article. If you still hav

    • Re: (Score:3, Interesting)

      by WalterGR ( 106787 )

      Firefox is not so closely tied to the OS that they could take this breach, elevate privileges and take over a system, like ActiveX vulnerabilities.

      Uh... not true at all. Firefox extensions can contain (and run) executable code.

      As the Greasemokey security vulnerability [oreillynet.com] demonstrated, web pages can "script" Firefox extensions.

      ActiveX = executable code + scripting from the web browser. Firefox extensions introduce the same risks as ActiveX.

      (addons.mozilla.org is having problems right now, otherwise I'

      • Ah, good. addons.mozilla.org seems to be responding again.

        So check out FoxyTunes [mozilla.org], which is listed on the Recommended Add-ons [mozilla.org] page.

        Download the XPI file, rename it to ZIP. Open it in WinZip or whatever. You'll notice several files:

        • FoxyTunes.dll
        • FoxyTunes.dll.linux
        • FoxyTunes.dll.mac
        • FoxyTunesBonobo.so.file

        DLL files are executable code on Windows. I'm assuming the *.linux and *.mac are similar. SO files are executable code under Linux, not sure why it has .file after it.

        I'm sure there are more

  • Sign your addons, please.. (Score:5, Informative)

    by QuantumG ( 50515 ) <qg@biodome.org> on Thursday May 31, 2007 @08:18AM (#19335979) Homepage Journal
    How to sign a Firefox Extension [mercille.org] by Frederic Mercille.

    It's not hard (for anyone who can make an add-on).

  • This is like handing out your car keys and then end up blaming Audi for it.

  • Subject to the laws of physics (Score:3, Insightful)

    by l0ne ( 915881 ) <`moc.liamg' `ta' `imonellim'> on Thursday May 31, 2007 @09:05AM (#19336621)

    Q: When am I at risk?

    A: When you use a public wireless network, an untrusted Internet connection, or a wireless home router with the default password set.

    That means that this attack only works if the local area network is hijacked! Which reduces its danger substantially for the population at large as the huge majority of home connections is on its own link.

    It is only a problem in the situation above (that are atypical nowadays) and in work or other large-network settings where it is possible to connect an untrusted computer to the network.

    IT ALSO MEANS IT IS NOT FIREFOX SPECIFIC, as hijacking a connection can lead to many unpleasant things that may be as dangerous as that without requiring Firefox (ie grabbing passwords!).

  • If the user is "insecure", then so too will the browser be. Anyone who would update software from a public wi-fi connection is in dire need of an education and asking for trouble. As far as extensions go, LESS IS MORE, as in beer: the browser will load faster, be less prone to memory leaks and XUL conflicts, and as the article suggests more secure to boot. Considerable skepticism should be given to any extension not found at the Mozilla site; if it were me I wouldn't install it, for the reasons above and
    • Note that one thing mentioned in the article was that the Google toolbar doesn't even ask. That is, you might update it without even knowing. If anything asks "do you want to update", you can always answer "no" (and are also noticed that there's an auto-update functionality running which you might be able to disable). However, if it just happens silently, then unless you already know that it happens, you'll probably not notice (at least until a new version with an user-visible change gets auto-installed).

  • This is crypto 101 (Score:1, Redundant)

    by mrkitty ( 584915 )
    Nothing new here please move along.
  • HTTPS just makes it hard to eavesdrop. It doesn't mean the site you are getting your plugin from isn't a spoofed one with a self-signed cert or that your legitimate location for downloading the plugin hasn't been hacked. I guess all of www.download.com downloads are vulnerable since they're sent over http or ftp - which is suceptible to attacks! Also, if your DNS (or host file etc) is owned/poisoned then I'd think your firefox plugin is the least of your concerns. Give me a break.
  • This is not an issue of http versus https. The only way for Firefox add-on updates to be secure, or any software updates to be secure for that matter, is for the software to make sure that the update code has been signed by the developer before installing the update. This is software updating 101. Impossible to spoof without the developer's private key.
  • Funny, I remember a time when people ran away from Internet explorer because of the potential for some very powerful and useful plugin technology (ActiveX) to be used against their computers.

    Everyone's websurfing saviour firefox is just as vulnerable it seems ... but everyone loves firefox and hates IE.

    I think this big warped shift in people's perception happened about the time when all those pesky Javascript haters (all slashdot readers just a couple years ago) fell in love with Ajax ... as if it wasn't si
  • How is this related to FireFox only?

    Doesn't the same apply for Windows Updates? A hijacked DNS can return a false address of a windows pdate server and have the user download vulns. instead of patches.

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