MacOS Kernel Flaw Could Allow Full-System Compromise

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A researcher going by the name “Siguza” unveiled a 15-year-old security vulnerability in Apple’s macOS operating system that could allow an attacker to fully compromise the system. The researcher also published proof-of-concept zero-day code to his GitHub page.

IOHIDeous

The flaw was called “IOHIDeous” by the researcher because it’s a vulnerability in the IOHIDFamily kernel extension that can be exploited by an unprivileged user. According to him, this kernel extension has been the culprit of many macOS security bugs in the past.

Siguza said he was looking for a “low-hanging fruit” bug in the iOS operating system, which shares the kernel with macOS. However, what he found is that some parts of IOHIDFamily exist exclusively for macOS. More specifically, it was the IOHIDSystem in which he found the flaw.

Impact

Attackers that exploit this flaw would need physical access to the user’s machine or some other way to exploit the machine first. Once the attackers are inside the machine, they can gain root privileges through this flaw, which means they will have full control of the system.

Normally, the attack works by logging out the user first, an action that could raise the alarm bells for users. However, this could be easily hidden by waiting for the users to log out or do a restart of the machine on their own. That’s when the attacker is able to obtain root privileges.

Patch May Not Come Quickly

Siguza didn’t contact Apple about the bug ahead of time and he published the bug in the last day of 2017, which means it will take some time for Apple’s security team to investigate the issue and release a patch.

The researcher released a proof-of-concept and more details about how someone could exploit and take over macOS machines. The proof-of-concept code specifically targets macOS High Sierra to show that the latest kernel protections don't work against it. The code should help Apple develop a fix faster, but at the time time this also made it easier for attackers to incorporate the flaw into their exploit tools.

Lucian Armasu
Lucian Armasu
Lucian Armasu is a Contributing Writer for Tom's Hardware US. He covers software news and the issues surrounding privacy and security.
12 Comments Comment from the forums
  • therealduckofdeath
    A rootkit as old as macos. Why aren't we surprised any more? Toy software for toy computers.
    Reply
  • therealduckofdeath
    *A rootkit as old as macos x. Why aren't we surprised any more? Toy software for toy computers.
    (I wonder why Tom's refuses to fix this annoying transferring between .co.uk and .com, that just breaks everything and constantly sends you to redirection error pages)
    Reply
  • bigpinkdragon286
    20550761 said:
    *A rootkit as old as macos x. Why aren't we surprised any more? Toy software for toy computers.
    (I wonder why Tom's refuses to fix this annoying transferring between .co.uk and .com, that just breaks everything and constantly sends you to redirection error pages)
    I could don the tinfoil hat and suspect it's likely Perch that doesn't care to pay for the fix. All of the bugs in the website seem to essentially cause users to reload the website, which in turn, causes the website to throw all the advertisements at a user's machine anew. So, if all of the flaws on Tom's website were corrected, I suspect revenue would go down, even if only slightly. That isn't likely to motivate management to fix things they don't have to deal with personally on a daily basis.
    In response to the article, it makes the talk of a Windows PC being less secure than an Apple PC sound like nothing more than a bunch of ignorance.

    Hopefully folks remember, or at least learn the reason OS 9 was replaced by a bought and paid for OS was (which Apple essentially customized), because Apple can't write good, long term software solutions. It seems the more Apple tinkers with the product they bought, the more problems the users end up with. This has been an ongoing problem for the company. How many people remember that Apple paid Microsoft to write some of their original software? Look how badly Apple software products perform on a Windows PC. The company has some pretty serious issues when it comes to making fast, stable, and secure, long term software solutions.
    Reply
  • Rodney Wilder
    As much as I'm not a fan of Apple products these days, I do find the way the researcher published this as quite sleezy. No prewarning to give time to fix, and providing proof of concept code on day of bug publication, all while doing this over a holiday.
    Reply
  • bigpinkdragon286
    20551063 said:
    As much as I'm not a fan of Apple products these days, I do find the way the researcher published this as quite sleezy. No prewarning to give time to fix, and providing proof of concept code on day of bug publication, all while doing this over a holiday.
    When you have companies that behave as unscrupulous as Apple, some people are willing to throw unsuspecting users under the bus to take a shot at them. On the other hand, this pretty much forces Apple to refrain from putting the fix on the back burner as they have done in the past. When Apple's automatic update software was causing drive-by-download attacks on Windows PCs, Apple seemingly couldn't be bothered to roll out a fix for about a half-year. There will probably never be a single correct approach to security, so we can argue the merits and flaws of this particular researcher's approach, but it's been the case in the past that sometimes a little arm twisting is necessary to make large companies take action.
    Reply
  • blppt
    "Hopefully folks remember, or at least learn the reason OS 9 was replaced by a bought and paid for OS was (which Apple essentially customized), because Apple can't write good, long term software solutions."

    Couple of issues with this, one, a good portion of what became OSX was developed at Next when Jobs was there, then he came back to Apple. Two, would anybody be complaining that Apple cant make their own OS if the exact same situation existed and Apple used Linux as the base for OSX instead of Mach/Darwin? Or some other flavor of Unix/Unix clones?

    As for the Windows performance of Apple apps, it might just have to do with competition. Why would apple go out of their way to make the Windows app work and perform as good as the Mac app when they are also trying to sell Macs? They'll make it work just well enough to not kill sales of their trendy portables for Windows users, while making the Mac experience that much better.
    Reply
  • wifiburger
    oh yeah, still waiting for Intel Virtual memory exploits to come out, enjoy that Intel cpu when apple applies the fix that hits 30% performance drop lol
    Reply
  • deepblue08
    Impossible, Mac has no vulnerabilities. *Takes coat*
    Reply
  • mrmez
    Not good especially for something so old. Surprising it hasn't been found before.

    Though by IT standards, it's assumed that all security measures are ineffective once you have physical access to a machine.

    And of course we won't get into any windows bugs, viruses, or even vendors putting key loggers in audio drivers.
    Reply
  • bigpinkdragon286
    20551322 said:
    "Hopefully folks remember, or at least learn the reason OS 9 was replaced by a bought and paid for OS was (which Apple essentially customized), because Apple can't write good, long term software solutions."

    Couple of issues with this, one, a good portion of what became OSX was developed at Next when Jobs was there, then he came back to Apple.
    When Jobs was there, at NeXT? Jobs founded NeXT, with employees that he took with him after leaving Apple. Jobs was never not a part of NeXT. Jobs didn't just come back to Apple so much as Apple reacquired him as a condition of their purchase of the NeXT company.

    NeXTSTEP, the NeXT operating system product, is an amalgam of the MACH kernel, BSD source code, and their own custom GUI work. For the most part, NeXT just used the existing, license-able UNIX software of the time and kernel research done by Carnegie Mellon, and built off of that.

    20551322 said:
    Two, would anybody be complaining that Apple cant make their own OS if the exact same situation existed and Apple used Linux as the base for OSX instead of Mach/Darwin? Or some other flavor of Unix/Unix clones?
    Probably.

    I suspect the same would be true for Microsoft or anybody else as well. If all Microsoft did was make their own distribution of Linux or UNIX, people would likely say they too didn't write their own operating system. Do folks insist that Red Hat has written their own OS? Apple should get credit where it's due, which is mostly in putting a pretty interface on something.

    20551322 said:
    As for the Windows performance of Apple apps, it might just have to do with competition. Why would apple go out of their way to make the Windows app work and perform as good as the Mac app when they are also trying to sell Macs? They'll make it work just well enough to not kill sales of their trendy portables for Windows users, while making the Mac experience that much better.
    It might have to do with the fact that instead of porting their software to work natively on Windows, they force it to work through a slow, bloated API wrapper.

    Reply