DIRTY COPY-ON-WRITE (aka Dirty Cow) is a vulnerability in Linux that has been lurking under the surface since 2007, but has only recently been exploited. And it is a massive vulnerability—it even gets its own logo. The vulnerability is in a part of the Linux kernel, so is present in virtually every Linux distribution, thus it affects a lot of Android phones as well. A malicious application can tamper with a read-only root-owned executable mapped into memory. The trick is to slip between the read and write parts of a copy, and redirect the operation. If that happens, it is potentially game over.
Apparently, Linus Torvalds tried to fix the problem 11 years ago, and failed, but thought it too difficult to exploit, so quietly walked away. Since then, changes…
