This issue got lost under the Qualys noise
The endianess handling for X Events assumed a fixed size of X Event structures and
had a specific 32 byte stack buffer for that.
However "GenericEvents" can have any size, so if the events were sent in the wrong
endianess, this stack buffer could be overflowed easily.
So authenticated X users could overflow the stack in the X Server and with the X
server usually running as root gaining root prileveges.
An information leak out of the X server due to an uninitialized stack area when swapping
Created attachment 486668 [details, diff]
Patch, concatenated from the above 4 commits.
The attached file is the patch, concatenated from the 4 above cited links.
For users' convenience, let me submit it.
These apply to <x11-base/xorg-server-1.19.4. xorg-server-1.19.5 is now stable.
Vulnerable versions removed in
Author: Matt Turner <email@example.com>
Date: Mon Oct 30 18:44:14 2017 -0700
x11-base/xorg-server: Drop vulnerable versions
security@: going to do anything with this?
(In reply to Matt Turner from comment #4)
> security@: going to do anything with this?
Thank you Matt, this report should have been closed with:
Marking as RESOLVED FIXED.