#linux kernelbugs overflowattack

The big news of course this week has been with the Facebook hacks (using the View As page and connecting to wish someone a Happy Birthday, then capturing the OAuth token to use for all connected apps).

However, there was also a Linux Kernel bug which is still affecting some of the distros still. 

Basically it is using an overflow in memory. I have seen it explained a few ways, one is with using long integers, and others explaining it is very vague ways. This article (from ThreatPost) seems to explain it in a way where we can get a good idea of what is happening and why the threat is “bad”.

Basically when a program is running it will be using up memory when this changes/increases there will be a page fault (there isn’t a clear path to the memory), the Linux Kernel is trying to run through and find accessible memory. There was a shortcut written to speed up the process tagging the Virtual Memory with a 32 bit identifier. That process lead to another problem where a something could be written to access already “used” memory, basically making memory vulnerable to an overflow by sending more than 32 bits. The fix was to bring the ending numbers for the Virtual Memory to 64 bits.

https://thehackernews.com/2018/09/linux-kernel-exploit.html