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Major Security Hole In Samsung Linux Drivers

Posted by kdawson on Wed Jul 18, 2007 07:55 AM
from the drive-a-truck-through dept.
GerbilSoft writes with news of a major security hole in Samsung's proprietary Linux printer drivers. From the Ubuntu Forums: "Just to inform you about a recent post on the French Ubuntu forum about Samsung drivers (sorry, in French). [Google translation here.] It appears that Samsung unified drivers change rights on some parts of the system: After installing the drivers, applications may launch using root rights, without asking any password. What is more, you may be able to kill your system, by deleting system components, generally modifiable only by using sudo." GerbilSoft adds: "Among the programs that it sets as setuid-root are OpenOffice, xsane, and xscanimage."
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  • Lazy Design... (Score:5, Insightful)

    by Azuma Hazuki (955769) on Wednesday July 18 2007, @07:57AM (#19898995)
    This sounds like a cheap hack. There is no need for these things to be setuid root, not on the program level. Sounds like someone is used to programming Windows drivers...

    I'm tempted to infer something sinister about this, but then I remember the old adage "never attribute to malice what can be explained by stupidity." It keeps your blood pressure nice and low.
    • Re:Lazy Design... (Score:4, Insightful)

      by EveryNickIsTaken (1054794) on Wednesday July 18 2007, @08:45AM (#19899383)

      Sounds like someone is used to programming Windows drivers...
      No, it merely confirms that there are lazy programmers creating crap code for all OSes, including Linux.
    • Re:Lazy Design... (Score:5, Interesting)

      by a.d.trick (894813) on Wednesday July 18 2007, @10:25AM (#19900663) Homepage
      I think lazy is pretty generous. Putting setuid root on something as powerful as openoffice is flat-out retarded, period. These guys are driver writers, they should know better than this. I mean they, really ought to know better than this. It would be like Red hat dumping ssh and recommending telnet for remote shell access and transfer of sensitive information.

      I don't see any reason to think something malicious of it, but I think this goes beyond stupidity. It's not quite as bad as distributing rootkits with your CDs, but I think it's getting there.
    • Re:Lazy Design... (Score:4, Insightful)

      by Liquidrage (640463) on Wednesday July 18 2007, @10:55AM (#19901121)
      A potential flaw in a linux driver from Samsung is blamed on MS, in 2 different manners no less, and it jets to +5.

      Classic /.
      • I'm going to reply to your post backwards, but you'll see why.

        Unix security if just flawed and the flaw is called "root".


        There is a fix for this flaw. It's called 'groups.'

        Only when the little bugger of an hotplug-manager changes the user id for the scanner device to the logged on user. Which still only gives one user access to the scanner. Have my Wife remote logged in and only one of us can use the scanner.


        This is distro-dependant. On Ubuntu, scanner access is controlled by groups. Want a user to be able to scan? You add them to the scanner group. You want someone to have access to burn CDs/DVDs? You add them to the cdrom group. If the scanner device is owned by any user, and owned by the group scanner, the permissions on the scanning device are set to group read/write, and both you and your wife are in the scanner group, then you both have access to the scanner. Try it yourself. Problem solved.

        BTW--with SANE, the best way to have two people access the same scanner is via the saned network sharing mechanism, which allows other systems using xsane (or other sane front-end) to access the scanner over the network without having to remote login.
          • by GooberToo (74388) on Wednesday July 18 2007, @09:30AM (#19899889)
            Which is why most distros support POSIX ACLs...they are just not widely used. Ext2, Ext3, JFS, XFS, and ReiserFS all support ACLs (extended attributes). I believe NFS version 3 and 4 also support ACLs.

            There are of course some other areas which ACL's don't address but there are pre-existing mechanisms to address those as well. Well, on most modern Unix/Linux systems anyways. The model has survived for so long for simple reasons; it's effective, simple and covers the vast majority of situations. When complex requirements come into light, more complex solutions exist. Most people just don't know about them.

      • Re:Lazy Design... (Score:4, Informative)

        by B'Trey (111263) on Wednesday July 18 2007, @09:01AM (#19899579)
        I can't tell you why the driver did what it did. However, from what I've read, the driver actually moves binaries to new locations and replaces them with a startup script which is set to run suid. That's way, way, way over the line. It breaks lots of stuff, like updates and patches. Someone doesn't deserver to be fired. Someone deserves to be tarred and feathered and banned from ever touching a computer again.
      • Re:Lazy Design... (Score:4, Insightful)

        by CastrTroy (595695) on Wednesday July 18 2007, @09:06AM (#19899625) Homepage
        The employee should be fired. They are the one who actually made the mistake, and who has shown they have no abilities. Managers shouldn't have to take the all the blame for their employees mistakes. If the manager has had a bad track record and this kind of thing happens too often, then maybe he should get fired, but you can't make the judgement that the manager should get fired every time an employee screws up.
  • Windows coders (Score:5, Insightful)

    by erroneus (253617) on Wednesday July 18 2007, @07:59AM (#19899011) Homepage
    If I'm not mistaken, this is how Windows got as bad as it is.

    This particular incident cannot be protested enough. If this sort of thing becomes common, End-user Linux will become as corrupted as Windows.
      • Re:Windows coders (Score:5, Interesting)

        by erroneus (253617) on Wednesday July 18 2007, @08:34AM (#19899277) Homepage
        No, that is not my point.

        As the PC developed, IO calls were to be linked through the BIOS. The idea was that each device was to have a ROM that linked itself to the system's BIOS and that there would be a more unified system for handling I/O. Well, for most people, BIOS wasn't fast enough so people started writing code to work around it. And that's where the PC's "bad programming habits" began and it just got worse from there.

        Now, instead of people using the Windows API properly, people are using undocumented APIs that are subject to undocumented change, people are still trying to squeeze more performance from their apps by moving code into ring-0 virtual driver code. If you don't already know, "ring-0" means the code has access to the entire machine and all memory. And when apps misbehave, they are flying without a net since the ring-1 and above offer levels of "protection" from misbehaving or malfunctioning apps.

        This culture of performance over stability and proper coding methods has undermined the security and stability of Windows. I'm not going to assert whether or not Microsoft is partly to blame or has any blame in this. But I will say that Windows coders have bad habits that are quite common and prevalent.

        As Linux coders grow in numbers, it is more and more important that things like abusing root or setting up kernel modules unnecessarily should be protested and prevented at every turn. To not fight it could result in the same problems and reputation that Windows now enjoys.
  • Thank you! (Score:5, Funny)

    by mwvdlee (775178) on Wednesday July 18 2007, @08:02AM (#19899031) Homepage
    A big "Thank You!" to Samsung for demonstrating that propriatory code is inherently less secure than open source, if only because you can (could) get away with insecure code.
  • by Simon (S2) (600188) on Wednesday July 18 2007, @08:06AM (#19899067) Homepage
    I find it very disappointing anyway that anything you install on ubuntu is installed as root (at least that is the default way of doing it). Wouldn't it be übercool to be able to install applications as the local user, and drivers maybe as the "driver" user? I still think The Zero Install system [0install.net] is a nice and secure way to install software, and maybe one day we can extend this to install drivers as well, so that root access will almost never be required (a bit like Plan 9, or what SE Linux is trying to do).
    • by vadim_t (324782) on Wednesday July 18 2007, @08:26AM (#19899213) Homepage
      Wouldn't change much really.

      This works OK for a multiuser system. If you run systems with 100 users on each and one gets their home directory hosed, you restore from backups and problem solved. Everybody else continues having uninterrupted service meanwhile.

      But on a personal box everything of importance is in $HOME anyway.

      What is needed is something like SELinux, which makes it impossible for applications to do things they shouldn't be doing.

      I say "something like" because SELinux is a very complicated system and AFAIK still badly documented. But it sounds like a step in the right direction.
    • by MrNemesis (587188) on Wednesday July 18 2007, @08:41AM (#19899355) Homepage Journal
      If you allow the local user to install programs, then the local user is either;
      a) going to need write access to all the usual locations (either /usr/bin and /usr/lib, or /opt) which wouldn't solve the problem TFA is on about
      b) going to need to use some middleware that *does* have rwx access to /usr and a fine grained ACL system dictacting which users have access to what

      "Driver" installs just need access to /lib.

      Fact of the matter is that whatever user/process has the rights to install apps has the rights to fuck them up as well. Much like how windows can't help it if the user runs trojan_setup.exe.

      As ther other poster noticed, things like SELinux offer incredibly fine grained access over what various users can and can't do, and if you go through the (fairly considerable) pain of setting it up it can give you an amazingly secure setup, but there's no way in hell it'd fly with everyday users or even most sysadmins. This is why Linux distros take such care with package management and like to retain control over their repositories - because they can't risk a third party, closed source package coming in and accidentally running a chmod -R 777 / on install. When you're dealing with companies that seemingly have little knowledge of Linux development and security models, this is a very real threat.
    • by rbanffy (584143) on Wednesday July 18 2007, @09:13AM (#19899701) Homepage
      Synaptic (and APT) are system-wide software-management tools and thus require root privileges. OTOH, it would be cool to be able to allow any user to install a program for himself and still keep it under package management.
  • It come out... (Score:5, Informative)

    by dmayle (200765) on Wednesday July 18 2007, @08:15AM (#19899143) Homepage Journal

    For those who can't read French, the Ubuntu forum is just a posting of a link to another forum where it was noticed. The posting, along with the interesting source can be found at http://linuxfr.org/forums/15/22562.html [linuxfr.org] The interesting parts are:

    wrap_setuid_third_party_application xsane
    wrap_setuid_third_party_application xscanimage

    wrap_setuid_ooo_application soffice
    wrap_setuid_ooo_application swriter
    wrap_setuid_ooo_application simpress
    wrap_setuid_ooo_application scalc

    The script copies the affected application's executable to one with a .bin extension, and replaces it with an suid wrapper script. This is undoable, but god, what a mess!

    Okay, I couldn't overcome the lameness filter, go to the source to see for yourselves...

  • by VE3OGG (1034632) <(ac.car) (ta) (GGO3EV)> on Wednesday July 18 2007, @08:45AM (#19899377)
    Hello,

    After I installed the unified drivers for my Samsung printer/scanner, I had the unwelcome surprise of discovering that OpenOffice now opens as root, and not only that but did not ask for my password!

    As a result, all documents I created were saved in the /root/ directory with super user rights. Practical and super secure!

    I attempted to re-install .Xauthority without success.

    The beast (the problem) is occuring under Ubuntu 7.04 under Gnome.

    Thank You.

    Bonjour,

    Après avoir installé les drivers unifiés de Samsung pour gérer mon imprimante scanner, j'ai eu la très mauvaise surprise de constater que la suite openoffice s'ouvrait en root et ceci sans que me soit demandé le moindre mot de passe !!!

    Du coup, les documents que je crée s'enregistrent dans le dossier /root/ avec des droits de super utilisateur. Pratique et super sécure !

    A tout hasard j'ai réinitialisé le .Xauthority : aucun succès.

    La bête est sous Ubuntu 7.04 et gnome. En attendant vote aide, je cherche et tente de résister au désespoir le plus sombre !

    Merci
  • Time to Get Heavy (Score:5, Insightful)

    by ajs318 (655362) <sd_resp2.earthshod@co@uk> on Wednesday July 18 2007, @08:48AM (#19899425)
    The proprietary driver fiasco has gone on far too long. It's time to stand up and say Enough Already!

    Let's all get writing to our elected representatives and demand that hardware manufacturers be obliged, by law, to provide detailed specifications which would enable a sufficiently-competent programmer to write a driver program enabling any of the features of their product to be used on any sufficiently-capable computer.

    Failure to do this places the rightful owners of hardware at a disadvantage. They can only use it in conjunction with certain Operating Systems. They are restricted to using it as the manufacturer thought fit. If a driver has a programming flaw, the user's computer can be compromised. If the Operating System is updated in such a way as the driver no longer works, the user is at the mercy of the manufacturer to release a new version of the driver -- or else the hardware is unusable (or at best, usable only through a bodge involving multi-booting: at the boot prompt, type linux to be able to use the Internet, or linuxOLD to be able to print).

    It's unfortunate, but this measure really needs to be brought in through legislation, because manufacturers will not do it voluntarily. There are two reasons: (1) they are paranoid of competitors {despite the fact that their competitors are busy reverse-engineering their products in secret while they reverse-engineer the competitors' products} and (2) they habitually lie through their back teeth in their advertising literature about the capabilities of their hardware, and such lies would be exposed with disclosure (e.g. a camera with a 2 megapixel image sensor, spitting out JPEG images interpolated up to 6 megapixels).
  • by Jerry (6400) on Wednesday July 18 2007, @08:58AM (#19899535) Homepage
    Here is a posting to the Ubuntu forum that is SEVEN MONTHS old and refers to postings A YEAR OLD!

    Printer drivers need to be installed with world execute permissions so that all users on the system can access the printer. The Samsung hacker's method of doing this, converting them to 4755 bin files and setting the original name as a link to the bin files, is one way of doing that -- IF his "unwrap" function had worked properly. That's the bug. Listed in the posting are files whose permissions need to be modified after the driver is installed.

    #1
    Old January 18th, 2007
    tweedledee tweedledee is online now
    Way Too Much Ubuntu

    Join Date: Dec 2006
    Beans: 252
    Ubuntu 7.04 Feisty Fawn User
    HOWTO Install Samsung Unified Printer Driver
    I had a fair amount of trouble initially getting my Samsung printer installed completely, but I finally have it all done, so here's a mini-guide for those who might benefit.

    NOTE: for the last few months, the Samsung website has been utilizing some buggy Flash code that will crash many (all?) Linux browsers that have Flash installed - hopefully they will fix this soon, but they don't seem in any hurry. Either use a secondary browser that does not have the Flash plugin installed (e.g., if you mainly use Firefox, you could use Epiphany (Gnome) or Konqueror (KDE)) or download the drivers via another computer/OS. Alternatively, again if you use Firefox, you can install the "flashblock" extension, usually this prevents the crash (and is useful for many of the other websites that have been appearing recently causing the same behavior, although it's not 100% successful).

    EDIT: The newest (as of this writing) driver from Samsung (20070324...) appears to solve some of the mfp/xsane issues, but also appears to missing a couple of library files. See post #23 for details. Also see posts #27-29 for details on ...plc errors and solutions.
    Post #35 suggets the 200704.... drivers have resolved this issue, so this may now be irrelevant.

    First, a disclaimer: much of the information I used came from this thread: http://www.ubuntuforums.org/showthread.php?t=28774 7 [ubuntuforums.org]. Another good source of information is http://www.linuxprinting.org./ [www.linuxprinting.org] Finally, I did this using the 20060719... and 20070125.... drivers; newer (or older) drivers may require some tweaks. Also, especially if you have a monochrome, non-duplexing, non-multifunction printer, you very well may have success with a generic post-script printer as a driver, without having to install the Samsung drivers. Also note that for my printer, pretty much all functions except duplex control worked even if I skipped steps 2-4 below (i.e., don't install the driver, only the relevant .ppd file) - which also has the advantage of not needing to fix xsane (additional step 2).

    This works for my CLP-550; similar steps seem to work for other Samsung printers not supported out-of-the-box with the drivers available in a fresh Ubuntu install. This is NOT a multi-function, multi-functions may require additional steps (but are discussed in other threads, a quick search should bring them up). Posts below from other users have reported sucess (sometimes with a couple of small modifications) with: ML-2510 (# 5, 14, 16, 26), ML-2510/XEU (# 18 ), ML-2571n (# 12), SCX-4200 (# 10), SCX-4521F (# 11), CLP-300 (# 35).

    1. Download and untar the driver from Samsung's website; for this example I will assume you untar it to ~.
    2. Open a terminal and navigate to ~/cdroot/Linux. I had to "chmod +w install.sh" to give write permissions, but that may be unusual. Edit install.sh as follows:
    a: change the first line from "#! /bin/sh" to "#! /bin/bash" (without the quotes)
    b (possibly not needed): change the line that includes "guiinstall.bin" (search for it, it's around line 1277) to eliminate the ".bin" (i.e

    • by Xiph (723935) on Wednesday July 18 2007, @08:06AM (#19899069)
      It's a driver installation, so the ordinary user doesn't/can't do it.

      However, it's a proprietary driver, that you need to install to use the printer, so if that's the printer you have people install it, expecting it not to create security holes.
      This might have been discovered earlier, if it weren't for the closedness of the source.

      My guess is that it happened due to a coder writing the driver so, it requires root to use it.
      Then trying to guess which programs requires the driver, then setting those to run as root. Silly, but easy to do.

      Sounds like it was done without peer review, so i guess they only have one guy writing their linux drivers..
      So why is it proprietary? well some places printers are encouraged(required) by law (enforcement) to leave secret and invisible watermarks.
      If it isn't done in the printer, it's done in the driver, if it's open, it'll be removed.
        • I agree, BUT (Score:5, Insightful)

          by PetriBORG (518266) on Wednesday July 18 2007, @08:27AM (#19899217) Homepage
          I agree with what you said, BUT...

          Stop with your lame "thousand eyes" theory. Apparently those thousand eyes couldn't see a permissions change on their own systems.
          This is uncalled for, because as can be see on the ubuntu forums [ubuntuforums.org] you can clearly see it was the "thousand eyes" reality that caught this problem in the first place and found the solution to remove parts from the install script.

          wrap_setuid_third_party_application xsane
          wrap_setuid_third_party_application xscanimage
          wrap_setuid_ooo_application soffice
          wrap_setuid_ooo_application swriter
          wrap_setuid_ooo_application simpress
          wrap_setuid_ooo_application scalc
          And the content of the function for suid-making functions etc. So I have to disagree with you there.

          I also agree with you though that linux distros should be automatically building in some sort of tripwire type setup to protect important system segments from scripts that are like this.

    • by Anonymous Coward on Wednesday July 18 2007, @08:13AM (#19899119)
      An app running as root can do anything it wants - and installers normally do run as root. The same problem exists on every OS: the administrator and the programs he runs can do retarded things.

      The question I want to ask is why there is a driver developer working for Samsung who is able to understand the function of the setuid bit but not the security implications of using it. It seems that there is a very special type of stupidity involved here, along with some extremely thoughtless design. Samsung is taking a big risk employing morons like that.

      If the guy can't understand the security implications of the setuid bit, which are well documented and not that complex, he should not be writing software.
    • Re:suid is evil! (Score:5, Informative)

      by nagora (177841) on Wednesday July 18 2007, @08:13AM (#19899121)
      Once more boys and girls, say it with me now, SUID IS EVIL! :-)

      SUID does not have to set id to root; my printing scripts are all setuid to "lp"; my mail servers are suid to "mail". This is a good thing.

      TWW

    • Re:to be fair (Score:5, Insightful)

      by Anonymous Coward on Wednesday July 18 2007, @08:23AM (#19899197)
      no user is going to be able to install such a dangerous "driver" without root access in the first place-- anyone can build a program, intentionally or accidently, that comprimises a system when ran/installed as root

      Yes, but when you install a driver, you normally assume that it's not going to make your system insecure. Why should it? Only a very badly designed driver would deliberately break your system security.

      Sometimes drivers do accidentally introduce security problems. The Nvidia drivers for X have done this in the past, for example. In those cases, it's not bad design, it's an oversight of some sort, like a buffer overflow.

      But this is not an oversight. A deliberate design decision has been made to break the Linux security model. A very special type of stupidity is involved: one that includes an understanding of the effects of the setuid bit, but excludes an understanding of the security implications.

      Samsung should investigate this fully - who knows what other retarded decisions have been made by these guys?
    • by east coast (590680) on Wednesday July 18 2007, @09:55AM (#19900209)
      This was an intentional attempt to create a backdoor.

      So when this same type of thing happens in Windows it's that Windows coders are inept but when the same happens in Linux it's because of a conspiracy? Please.

      The Linux community better be damn well ready for when this becomes commonplace as more people use Linux. I don't expect it as much from real vendors but it's going to happen more from the likes of amateur coders and malware producers.

      Too many have fallen pray to the myth that Linux isn't going to have some of the same issues that Windows has with these areas in software. This incident alone shows that Linux will not be immune to those who don't care enough, don't know enough or are willing enough to sacrifice system security for whatever reasons.