Android Patch For High-Severity 'Dirty COW' Linux Kernel Flaw Delayed For At Least Another Month

Google published its November security bulletin describing all the recent patches for vulnerabilities in Android, but a major one seems to be missing. The Linux kernel vulnerability, called “Dirty COW,” affects all Linux and Android devices that use kernel version 2.6.22 or newer and is a "High-Severity" bug that allows remote privilege escalation and can’t be mitigated by existing OS protections.

Linux Bug Of The Decade

Dirty COW has been considered one of the most serious Linux bugs of recent years, not just because it allows privilege escalation (something many bugs are capable of doing), but also because it affects all Linux and Android devices from the past decade. Worse yet, because it's such an old bug, it may also be under active exploitation (or if it hasn't been so far, it certainly will be now that it's public). This bug gives attackers around a billion and a half targets, unless those devices are patched soon, something that's much easier said than done for Android.

Dirty COW has been so named because the bug affects the Copy On Write (COW) resource management mechanism. An unprivileged local user could gain write access to what would otherwise be read-only memory and then increase their privilege on the system.

The bug was first discovered in May, but it was revealed to the public just last month after a coordinated effort by security researchers to create a fix before everyone, including potential attackers, learned about it.

Why A Dirty COW Patch Isn’t Yet Available For Android

Linux users have already started applying the Dirty COW patch to their systems, but Android users won’t be as fortunate. As Google makes new patches for Android vulnerabilities a month after they’ve been given to the OEMs, the Dirty COW patch couldn’t land in the November security update. This process exists so Google can coordinate with OEMs, so they can release the patches for their own devices roughly around the same time as Google makes them public.

The coordinated release also ensures that at least some devices get fixed for the vulnerabilities that are made public. However, those that get no updates (or won't get any for some time) may still remain exposed to new attacks that take advantage of the new software flaws.

Other Serious Flaws Fixed In The November Update

The Android team found only two critical vulnerabilities in the latest version of Android itself, which is an improvement from the previous two months. However, one of those flaws is related to the mediaserver library once again. Despite the sandboxing of various mediaserver library components in Android 7.0, the team is still able to find more critical or high-severity bugs in it almost every month.

Other high-severity and moderate flaws were also found in this library, as well as in the graphics, Bluetooth, OpenJDK, System UI, Android Runtime, and even the BoringSSL crypto components of the operating system. Google also found multiple critical and high-severity bugs in Qualcomm’s crypto and camera drivers, as well as in Nvidia’s GPU drivers.

Google’s monthly security bulletins and patches have been a step forward for the security of the Android ecosystem, but it also showed just how vulnerable unpatched Android devices could be--Google finds dozens of new critical-, high-, and moderate-severity Android bugs every month.

Google may still be able to protect the majority of users against these attacks through its anti-malware service (“Verify Apps”), but this likely doesn’t work as well for targeted attacks against individuals or even against small-scale (sub-100,000 users) infections that may harder to identify quickly in the wild.

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  • alextheblue
    Just like I said in the article where Google gave MS 7 days before going public. They've known about this since May and it's just being talked about, and still not patched. Oh and when they do patch it 90% of Android devices will remain vulnerable for an unknown amount of time, many will never get patched.

    Oh and if you look around it IS being exploited in the wild and has been for some time. It's actually quite an old bug (years old), and the people exploiting it sure aren't talking about it. So who knows how far back abuse of the flaw goes. But I think 7 days should be enough, right Google?
  • ZolaIII
    It's fair to say we made a RAM stakes from this one long time ago on Android. The ports of original Linus patch for variety of kernel versions used on Android (from 3.4 up) is available for quite some time. I know for sure it's officially merged in CM 14 along with various costume kernel builds. At least to say that a this one will be patched on most Android devices that still have running development thank to its popularity. For a devices that come DOA or didn't have maintenance for long periods of time answer is simple don't buy from that brand ever again.

    Thing that passes me most is that their is a lot of similar security flaws that don't get any press attention. On open platform with such a much eye's put on it (code) at least flaws are quickly spotted & patched & that is something we simply can't say for any other closed source one.
  • extremepenguin
    7 Days Google, that was your limit you have now had 7 Months and there is still no patch. Hippocrite much?