Last week, I gave a talk at the CharmBUG meetup on the recent Xorg vulnerability that allowed for local users to elevate their privileges through a vulnerability in the Xorg command line options. The vulnerability allowed users to overwrite files and run code as the root user. The original vulnerability was found in recent versions of Xorg on Debian, RHEL, and CentOS, but was not patched in OpenBSD until the details of the vulnerability were released. Credit for the vulnerability discovery goes to Narendra Shinde, with Matt Hickey providing an exploit for OpenBSD. You can find the slides from the talk here:
CharmBUG Presentation 11/28/18 - https://github.com/charmbug/presentations/blob/master/2018-11-28:XorgandFunWithLocalRootPrivileges.pdf