Surfing porn on your Mac isn’t as private as you might think

“Surfing porn in Google Chrome’s Incognito mode lets you check out all the sex you want without anyone being the wiser, unless you’re on a Mac,” Jeff Gamet writes for The Mac Observer. “Evan Andersen found a bug in Chrome that left his fun time activity loaded in his NVIDIA graphics card memory — a bug that NVIDIA claims is actually Apple’s fault.”

“Incognito mode is a feature that doesn’t log your browser history or keep cached images, both of which are especially handy if you don’t want anyone knowing what you’re looking at online,” Gamet writes. “In Mr. Andersen’s case, however, the images he was checking out a few hours earlier popped up on his display when he started to play Diablo III. Instead of seeing the usual splash screen as the game loaded, he saw a jumble of porn shots he checked out prior launching the game.”

Gamet writes, “‘So how did this happen? A bug in Nvidia’s GPU drivers,’ Mr. Andersen said.”

Read more in the full article here.

GPU memory is not erased before giving it to an application. This allows the contents of one application to leak into another. When the Chrome incognito window was closed, its framebuffer was added to the pool of free GPU memory, but it was not erased. When Diablo requested a framebuffer of its own, Nvidia offered up the one previously used by Chrome. Since it wasn’t erased, it still contained the previous contents. Since Diablo doesn’t clear the buffer itself (as it should), the old incognito window was put on the screen again. — Evan Andersen

“But this isn’t Nvidia’s fault. At least, according to Nvidia,” Emil Protalinski reports for VentureBeat. “‘This issue is related to memory management in the Apple OS, not NVIDIA graphics drivers,’ a Nvidia spokesperson told VentureBeat. ‘The NVIDIA driver adheres to policies set by the operating system and our driver is working as expected. We have not seen this issue on Windows, where all application-specific data is cleared before memory is released to other applications.'”

“Anderson wrote a program to reliably reproduce the bug by scanning the GPU’s memory for non-zero pixels. The tool was able to reproduce a Reddit page closed on another user account, down to each and every pixel,” Protalinski reports. “Some Reddit users are reporting this issue also occurs with AMD graphics cards, adding to the validity that this is an OS X issue not an Nvidia one.”

Read more in the full article here.

MacDailyNews Take: Forget porn for a moment. If it can reproduce a Reddit page, it can reproduce anything, right? Like bank websites and such?

Of course, physical access is necessary; this doesn’t work any other way, but this bug should still be fixed.

21 Comments

  1. Lesson here is:
    Do not install anything other browser but Safari and avoid those nasty back stabbing plug-ins.
    Chrome is interesting yet did you really think Froogle would protect you?

    1. And let’s beat the dead horse again:
      Despite Google’s much acclaimed Project Zero work finding security holes in everyone else’s software, they’re doing a lousy job finding them in their own. We’re going to hear this again and again and again until Google get’s their own act together.

    2. Sorry guys. This is not chrime’s fault.

      I have seen this behavior before. But I experienced this with Safari. (Not with porn, ok)

      I was in “private mode”. Then switch out. Although I can’t always replicate it, every now and again I will see my private browser image display prior to the in-private page.

      I never use google products. I have seen this behavior on my iPhone as well.

      If there is shared code between the platforms, it’s gotta be in there somewhere.

  2. I love the Pass-The-Buck on this oh-so-typical memory mis-management issue. All of the companies involved can be stuck with the responsibility. ALL of them.
    – Nvidia
    -Google
    -Apple

    There has to be a revolution in coding whereby memory management is put in a top priority spot for debugging. So far, all we’ve had are vacuous promises (i.e. Java) that it’s gonna happen. I’m still waiting for definitive verification that Apple’s Swift programming language solves it definitively. Until then, bad memory management tops the list of sources of software security holes. #1.

  3. I refuse to click on “read full article here” links when the headline says something general about the Mac OS but the body reports a problem with 3rd party software. If you install anything from Google, you get what you deserve, in my opinion.

  4. If anyone bothered to go to the main article you would find this little gem.. “But this bug isn’t limited to just Chrome’s incognito mode — anything that appears on your screen is up for grabs.” In other words, it didn’t matter if it was Chrome, Safari, Opera, etc. or any other application with a visual interface. If it was displayed on screen, it may be in the graphics buffer. If Nvidia’s claim that it doesn’t happen on Windows machines where the HW could be any number of different configurations, the blame if any would reasonably fall to the OS/driver.

      1. There was an update at the bottom of the article that says the same problem occurs for AMD graphics cards also strengthening the case that OS X permissions may be at fault.

    1. Apple certainly isn’t perfect, and is appears to be an example of a fairly basic programming error. It does not appear to be exploited at this point, and I am not even sure that there is much opportunity to exploit it. Fortunately, this also appears to be a fairly easy bug to fix and quickly release as an iOS update.

  5. Maybe they have done this on purpose to catch purveyors and consumers of illegal material like child porn or how to organize a suicide attack to kill people. I’m not so sure it is such a bad thing that only the address of the site is not kept in history but a graphic record of what was watched could be revealed. Yes, a sensitive issue but if this is how they find out that the Gary Glitters of the world are pedophiles, is it such a bad thing? If that is NOT what it is there for, then by all means, its a bug that should be fixed.

    1. That would be an interesting conspiracy theory. Fortunately it seems to be a fairly easily fixed OS X driver permission problem with Nvidia and AMD (so far) graphics cards.

  6. “… if you don’t want anyone knowing what you’re looking at …”

    This is misleading. In first order, incognito mode of a browser extends ONLY to users of this particular computer. Your ISP, for instance, must know what you’re looking at, and they know what IP address you use at the time (otherwise, it wouldn’t work).

    Sure, there may be malware which could read that and deliver this info to a remote computer/user, but preventing that is computer security 101.

    So, the only people incognito mode hinders are your family/spouse/coworkers, and police who needs a warrant (by which time you hopefully have cleared your cache anyway).

    No one uses my Mac on a routine basis, and I’m not embarrassed to admit to looking at porn anyway. I only do not look into what might be considered illegal, so police stepping in is pretty unlikely, too. So all this is pretty useless to me (and, in fact anyone else who knows how things work).

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