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Homemade PDF Patch Beats Adobe By Two Weeks

Posted by kdawson on Mon Feb 23, 2009 07:54 PM
from the p-d-q dept.
CWmike writes "Sourcefire security researcher Lurene Grenier has published a home-brewed patch for the critical Adobe Reader vulnerability that hackers are exploiting in the wild using malicious PDF files, beating Adobe Systems Inc. to the punch by more than two weeks. Grenier posted the patch on Sunday with the caveats that it applies only to the Windows version of Adobe Reader 9.0 and comes with no guarantees. Also, PhishLabs has created a batch file that resets a Windows registry key to de-fang the hack by disabling JavaScript in Adobe Reader 9.0, giving administrators a way to automate the process."
+ -
story

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[+] Adobe Flaw Heightens Risk of Malicious PDFs 193 comments
snydeq writes "Security companies warn of a new flaw in version 9 of Adobe Reader and Acrobat that could compromise PCs merely by the opening of a malicious PDF. Although attacks are not yet widespread, hackers are exploiting the flaw in the wild, gaining control of computers via buffer overflow conditions triggered by the opening of specially crafted PDFs." Adobe is calling the flaw "critical" and says a patch for Reader 9 and Acrobat 9 will be released by March 11.
[+] Attackers Infect Ads With Old Adobe Vulnerability 70 comments
thethibs writes "eWeek is reporting that just as everyone is buzzing about the latest Adobe vulnerability, someone poisoned ads hosted by Ziff-Davis with an older Adobe exploit (affecting versions 8.12 and earlier, and long since patched). Z-D fixed the problem less than 24 hours after its first appearance. The interesting bit of this is that a bunch of people probably got hit with the old Trojan when they browsed to a story about the new one."
[+] Adobe Confirms PDF Zero-Day, Says Kill JavaScript 211 comments
CWmike writes "Adobe Systems has acknowledged that all versions of its Adobe Reader, including editions for Windows, the Mac and Linux, contain at least one, and possibly two, critical vulnerabilities. 'All currently supported shipping versions of Adobe Reader and Acrobat, [Versions] 9.1, 8.1.4 and 7.1.1 and earlier, are vulnerable to this issue,' said Adobe's David Lenoe said in a blog entry yesterday. He was referring to a bug in Adobe's implementation of JavaScript that went public early Tuesday. A "Bugtraq ID," or BID number has been assigned to a second JavaScript vulnerability in Adobe's Reader. Proof-of-concept attack code for both bugs has already been published on the Web. Adobe said it will patch Reader and Acrobat, but Lenoe offered no timetable for the fixes. In lieu of a patch, Lenoe recommended that users disable JavaScript in the apps. Andrew Storms, director of security operations at nCircle Network Security, said of the suggestion in lieu of patches, 'Unfortunately, for Adobe, disabling JavaScript is a broken record, [and] similar to what we've seen in the past with Microsoft on ActiveX bugs.'"
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  • Registry hack (Score:5, Interesting)

    by coulbc (149394) on Monday February 23 2009, @08:00PM (#26964343)

    We figured that one out in about five minutes. Wrote a quick group policy file and moved on to the next problem.

    • So is this "user supplied" PDF fix an example of how Open Source is More Secure than Closed Source?

      OSS users supplied a fix in less than a day, whereas a closed source programmer in some cubicle somewhere will take weeks to do the same. Maybe this would be a fine example to present to the UK Parliament and U.S. Congress, in order to convince them that open source is the best path to follow.

      • Re:Registry hack (Score:5, Informative)

        by initialE (758110) on Monday February 23 2009, @10:59PM (#26965533)

        For myself I just used the REG.exe located inside the %system32% folder. in your logon script (assuming you have one), just add in the lines

        REG add "HKCU\Software\Adobe\Acrobat Reader\9.0\JSPrefs" /v bConsoleOpen /t REG_DWORD /d 0 /f

        REG add "HKCU\Software\Adobe\Acrobat Reader\9.0\JSPrefs" /v bEnableGlobalSecurity /t REG_DWORD /d 1 /f

        REG add "HKCU\Software\Adobe\Acrobat Reader\9.0\JSPrefs" /v bEnableJS /t REG_DWORD /d 0 /f

        REG add "HKCU\Software\Adobe\Acrobat Reader\9.0\JSPrefs" /v bEnableMenuItems /t REG_DWORD /d 0 /f

        YMMV. REG.exe is not included on Windows 2000. Because this applies to the current user registry there should be no permissions issue. And make sure your path does include the system32 directory as by default.

  • Feature Request (Score:5, Insightful)

    by ewhac (5844) on Monday February 23 2009, @08:06PM (#26964393) Homepage Journal
    Since Adobe seems to (incorrectly) think JavaScript inside PDFs is a great idea, how about adding this feature:

    When loading a PDF, if Reader sees there's JavaScript that wants to run, Reader pops up a dialog along the lines of, "Hey, this file contains executable code which is, y'know, kind of contrary to the whole concept of a 'document'. Do you want to allow the code to run? [Yes] [[Hell, No]]"

    This is the cheesy but mostly effective stopgap solution Microsoft adopted when Word became an infection vector for macro viruses. Unless Microsoft got a patent on it, I don't see any reason why Adobe couldn't also use the same approach.

    Schwab

    • Re:Feature Request (Score:5, Insightful)

      by tkdrg (1484293) on Monday February 23 2009, @08:17PM (#26964479)

      When loading a PDF, if Reader sees there's JavaScript that wants to run, Reader pops up a dialog along the lines of, "Hey, this file contains executable code which is, y'know, kind of contrary to the whole concept of a 'document'. Do you want to allow the code to run? [Yes] [[Hell, No]]"

      Do you think that the average user will read anything before clicking "Yes"?

      • by MMC Monster (602931) on Monday February 23 2009, @08:41PM (#26964653)

        How about: "Do you want to prevent the execution of possibly malicious code in this .PDF file?" [Yes][No].

        If they select No, the next dialog is: "Fine. I've just opened all the ports on the computer, deleted the last 10 documents you opened up, and loaded up a couple trojans. Are you sure you want to run the executable code in this PDF file now?" [Yes][No].

        This way, the user won't be taught to always select the same confirmation box all the time.

      • Re:Feature Request (Score:5, Insightful)

        by Mr. Roadkill (731328) on Monday February 23 2009, @08:49PM (#26964721)

        Do you think that the average user will read anything before clicking "Yes"?

        ...of course they won't, which is why you turn it around to "Hey, this file contains executable code which is, y'know, kind of contrary to the whole concept of a 'document'. Do you want to block execution of this code? [Yes][No, I like to live dangerously]".

          • And this is why we need to get away from labeling dialog box buttons "Yes", "No", "Cancel", etc. We can label them anything we want, so why not be descriptive? Try "Safe", "Unsafe", "Really Stupid", "Don't click this -- ever!"

            The same applies to the save dialogs. I like how OO.org 3.0 handles the "Do you want to save?" dialog when closing the program: The buttons are labeled "Save", "Discard", and "Cancel". Of course, "Cancel" could be better described as "Return to Program."

    • Agreed, why would one want another programming language embedded in a programming language? Postscript already can do all you would want. It is a bit hairy programming, but it can be done (see f.x. http://www.physics.uq.edu.au/people/foster/postscript.html [uq.edu.au]). The best way to mitigate security issues with embedded code is to eliminate the execution. That is, until some one writes a javascript interpreter in postscript.

      • Re: (Score:3, Informative)

        PDF is not PostScript. It shares some concepts (such as the imaging model and a good many keywords), but it is not a programming language. It has no control constructs, for example.
    • Re: (Score:3, Interesting)

      by Anonymous Coward

      I'm going to have to disagree...

      Allowing some scripting in a document is great. For example, I'm writing a math textbook [wordpress.com]. If PDF-javascript had a FOSS implementation, I'd use it to make interactive quizzes and questions in it. Sadly, while LaTeX has a package to do this, there is no support.

      Before someone goes and says that I shouldn't be using a PDF in this case, please think. I'm writing a large textbook with lots of graphics. I want it to be in a single file so that its easily available to the technical

    • Re:Feature Request (Score:5, Informative)

      by klossner (733867) on Monday February 23 2009, @08:26PM (#26964537)

      Adobe did add this dialog -- but it only appears if you have disabled Javascript! (Which you can do with Edit / Preferences, no need for the registry hack.)

      Here's the exact dialog:

      ? This document contains JavaScripts. Do you want to enable JavaScripts from now on? The document may not behave correctly if they're disabled.

      [ ] Don't show this message again until this document is reopened

      [[Yes]] [[No]]

    • Re: (Score:3, Interesting)

      Feature request: a NoScript equivalent for Acrobat Reader.

  • JavaScript?! (Score:5, Insightful)

    by Anonymous Coward on Monday February 23 2009, @08:08PM (#26964415)

    Seriously, JavaScript? In a PDF file? Why would you do that?

    • by IceCreamGuy (904648) on Monday February 23 2009, @08:11PM (#26964435) Homepage
      Uh, duh, to get on the front page of /.
    • Re:JavaScript?! (Score:5, Insightful)

      by TheRealMindChild (743925) on Monday February 23 2009, @08:48PM (#26964713) Homepage Journal
      PDF seems to be the poster child for "How to abuse a format in a way that is contrary to its nature". Clients send us PDF's FORMS now... that they want us TO EDIT! Not print out, hand write on, and perhaps fax back... but EDIT IT, like it is a Word Processor document. Explaining to these people why this is an abomination is like telling a hooker not to sleep with the guy with sores all over his body... it falls on deaf ears, and makes baby Jesus cry.
      • by Penguinshit (591885) on Monday February 23 2009, @09:14PM (#26964933) Homepage Journal
        I actually used JavaScript in PDF to create interactive forms for the corporate intranet. It was pretty because I could use Photoshop to create the underlying image.

        Then I quit drinking and realized Excel with tweaked permissions was far better suited to the task. It wasn't as smooth looking but it was easier for my staff to update.
      • by Main Gauche (881147) on Monday February 23 2009, @09:29PM (#26965015)

        Pardon my ignorance, but exactly what other format should one use if one wants to use forms?

        In my place of work, a large group of individuals each needs to fill out an annual form. It contains some short-answer questions, and a few that requires a few paragraphs to answer. In the past, they have used... wait for it... Word. Yes, I was forced to boot up Word once a year, to fill out this form. You should see the completely disastrous document that results.

        For that reason, I always wished our administrators would have figured out pdf forms. You don't "edit" them, as you say; you fill them in. While there are many complaints to make about Adobe, I don't see the problem with pdf forms. Am I missing something?

  • by Anonymous Coward

    JavaScript in PDFs is, and always has been, a bad idea. I started disabling it years ago when it first showed up, and am continually frustrated that it is present, let alone enabled by default. How many PDF exploits have relied on JavaScript? I haven't been counting, but it sure seems like most of the vulnerabilities are either through JavaScript or made much easier to exploit by its presence.

    Someone is doubtless going to say that JavaScript is critical to PDFs as a helper for filling in forms. OK, whatever

  • by fm6 (162816) on Monday February 23 2009, @08:20PM (#26964497) Homepage Journal

    You skip all testing. Just the sort of thing I want to install in my system.

  • Wow (Score:5, Funny)

    by ClosedSource (238333) on Monday February 23 2009, @08:20PM (#26964501)

    You mean an individual who doesn't have a business to protect or any customers is able to come up with an un-QA'd version faster than the company that produced the product. Amazing!

  • Patch? (Score:2, Interesting)

    So this patch basically does the equivalent of a user going into the program's settings and disabling the JavaScript execution checkbox? Hmmm, I don't want to post this anonymously, so I'll apply one of my homebrew patches to uncheck the "Post Anonymously" checkbox. Wow, I'm l33t!
  • by Facegarden (967477) on Monday February 23 2009, @08:31PM (#26964587)

    What i find more interesting is how slashdot is now able to tell the future!
    The article boldly claims that something released yesterday has arrived two weeks before the official patch. Now, i know it's possible that the two weeks was taken from Adobe's projected patch fix date, but projections and fact are still different, and journalistic integrity requires a writer in this situation to indicate directly that this two weeks is not actually fact, as we couldn't know that yet. The headline is an outright lie, as far as i can tell, as it relies on future events being a certain way.

    Can we not have articles started with lies on slashdot from now on? Maybe keep the lies towards the end?
    -Taylor

  • by thePowerOfGrayskull (905905) on Monday February 23 2009, @08:34PM (#26964603) Homepage Journal

    As anyone who has developed complex software with a large installed userbase can attest to, you /cannot/ simply slap together a fix and push it out to millions of people.

    Even the simplest one line code change change requires extensive (if targeted) testing when you operate on that scale - the consequences of an "oops" that could result from a hasty fix could easily get far worse than the original issue.

    • by AngryNick (891056) on Monday February 23 2009, @09:25PM (#26964991) Homepage Journal

      - the consequences of an "oops" that could result from a hasty fix could easily get far worse than the original issue.

      Do you really believe that? I appreciate the need for caution and measured risk taking before releasing new code, but taking _weeks_ to test a reg hack/kill switch just tells me that a company isn't taking their defects very seriously. I'd be much more forgiving of a company that screwed up a patch than one that sat on it until it was too late.

  • by Anonymous Coward on Monday February 23 2009, @08:41PM (#26964659)

    Lurene Grenier has published a home-brewed patch for the critical Adobe Reader vulnerability ... beating Adobe Systems Inc. to the punch by more than two weeks.

    What the fuck Adobe? What did you do for those extra two weeks?

    it applies only to the Windows version of Adobe Reader 9.0 and comes with no guarantees.

    Oh ... I guess you were trying to make it work on all systems, and checking to make sure that it didn't royally fuck up the user's computer, or introduce another, potentially more serious vulnerability.

  • Really? (Score:5, Funny)

    by tool462 (677306) on Monday February 23 2009, @08:44PM (#26964679)

    "caveats that it applies only to the Windows version of Adobe Reader 9.0 and comes with no guarantees."

    My boss will be pleased. I can push all my releases up at LEAST two weeks earlier now by adding this caveat on to all of my code. Thanks, Geritol.

  • by UtucXul (658400) on Monday February 23 2009, @08:52PM (#26964745) Homepage
    I'm not sure I understand the overwhelmingly negative reaction to javascript in pdf files. I realize that there is a danger in allowing executable content in files (and it is arguable whether or not the danger is worth it) but I do not understand why so many people don't seem to understand that there are at least possible benefits to it.

    I used to make slides for talks using LaTeX. There are great ways to include animations directly in the pdf that use javascript. I always had far less trouble getting my animations to play than other people at conferences I went to because acrobat reader was all I needed and it is nearly always there. And for the record, the animations were things I really needed since they showed output from simulations.

    I've also seen lots of forms that do some math or validation. How do people think that happens?

    Again, I think we need to be very careful about executable code but that doesn't mean there are no possible good uses for it.

    • by Tikkun (992269) on Monday February 23 2009, @09:09PM (#26964881) Homepage

      I'm not sure I understand the overwhelmingly negative reaction to javascript in pdf files.

      Please read the 10 immutable laws of security [microsoft.com]. The one you're looking for is the first one on the list:

      "If a bad guy can persuade you to run his program on your computer, it's not your computer anymore."

      • Re: (Score:3, Insightful)

        "If a bad guy can persuade you to run his program on your computer, it's not your computer anymore."

        Is that referring to Bill Gates?

    • I'm not sure I understand the overwhelmingly negative reaction to javascript in pdf files.
      ...
      There are great ways to include animations directly in the pdf that use javascript.

      Hmm.... I think I see a connection here.

    • Re: (Score:3, Informative)

      I like the way Apple approaches that problem in their Quartz Composer tool. Basically you have JavaScript for all types of funky validations, requests and calculations you would like to do but the 'vulnerable' classes that would allow reading/writing local files, networking or creating annoying popups have been removed.

  • A better patch... (Score:4, Insightful)

    by Kazoo the Clown (644526) on Monday February 23 2009, @09:01PM (#26964815)
    My patch for Adobe is to uninstall reader and use Foxit instead. I thank those on Slashdot who alerted me of its existence as I have longed for a viable alternative from Adobe crapware for ages. It constantly was popping up windows where I would click "don't show me this again" about issues that were relevant to Adobe but not to me, and it never seemed to remember the setting once I checked on it. Worst designed junk I've ever seen. I've since found that Foxit is considerably faster as well.

    Good riddance.
      • Re: (Score:2, Funny)

        by Anonymous Coward

        Thank you for letting the Slashdot community know what you find offensive... is this because you think it's interesting, or because you have no friends to talk with?

        • by Anonymous Coward on Monday February 23 2009, @08:24PM (#26964521)

          I'll go for the secret third option, "because she's a feminist". Letting the world know what they find offensive is practically the feminists' national sport. Rather, it would be if they had their own country. And by God, I wish they did.

          • by Anonymous Coward on Monday February 23 2009, @08:49PM (#26964727)

            Q: How many feminists does it take to change a lightbulb?
            A: That is NOT funny.

            • by JorDan Clock (664877) <jordanclock@gmail.com> on Monday February 23 2009, @09:42PM (#26965077)
              Q: How many feminists does it take to change a lightbulb?

              A: Four. One to change the lightbulb, three to form a support group.

              But really, it's a trick question because feminists can't change anything.
              • Unrelated to the feminist jokes, but related to lightbulbs:

                Q: How many psychiatrists does it take to change a lightbulb?
                A: Only one, but the lightbulb has to want to change.

                  • Re: (Score:3, Funny)

                    One to change the light bulb and to post that the light bulb has been changed.

                    Fourteen to share similar experiences of changing light bulbs and how the light bulb could have been changed differently.

                    Seven to caution about the dangers of changing light bulbs.

                    Seven more to point out spelling/grammatical errors in posts about changing light bulbs.

                    Five to flame the spell checkers.

                    Three to correct spelling/grammar flames.

                    Six to argue over whether it's "lightbulb" or "light bulb" ... another six to condemn those

          • Dude, you should really be careful. I don't think you realize who you're talking to. [xkcd.com]

            Posting AC is only going to keep you safe for so long.

            That also goes for everyone who modded her down.

      • Re: (Score:3, Insightful)

        Your grandchildren are not likely to be browsing Slashdot. Furthermore, taking offense to something that is very clearly tongue-in-cheek is not befitting of someone of your age.

      • So, you're saying your grandmother couldn't install the patch? Or are you trying to imply that your 13 year old or younger grandchildren are nerdy enough to read slashdot?
      • by Anonymous Coward on Monday February 23 2009, @08:45PM (#26964687)

        Yeah, you're right. It's terrible when people use an apostrophe when they mean "your".

    • by Lead Butthead (321013) on Monday February 23 2009, @08:14PM (#26964455)

      Lurene Grenier to Adobe: Pay up! We solved your issue.

      Adobe to Lurene Grenier: You decompiled Acrobat in some way to create this fix, in violation of click-through license and DMCA (not to mention making us look incompetent.) We're suing you and we're going to make sure your government put you away in a pound-you-in-the-ass prison for a long long time.