USN-3362-1: X.Org X server vulnerabilities

Ubuntu Security Notice USN-3362-1

24th July, 2017

xorg-server, xorg-server-hwe-16.04, xorg-server-lts-xenial vulnerabilities

A security issue affects these releases of Ubuntu and its
derivatives:

Ubuntu 17.04
Ubuntu 16.04 LTS
Ubuntu 14.04 LTS

Summary

Several security issues were fixed in the X.Org X server.

Software description

xorg-server
– X.Org X11 server
xorg-server-hwe-16.04
– X.Org X11 server
xorg-server-lts-xenial
– X.Org X11 server

Details

It was discovered that the X.Org X server incorrectly handled endianness
conversion of certain X events. An attacker able to connect to an X server,
either locally or remotely, could use this issue to crash the server, or
possibly execute arbitrary code as an administrator. (CVE-2017-10971)

It was discovered that the X.Org X server incorrectly handled endianness
conversion of certain X events. An attacker able to connect to an X server,
either locally or remotely, could use this issue to possibly obtain
sensitive information. (CVE-2017-10972)

Eric Sesterhenn discovered that the X.Org X server incorrectly compared
MIT cookies. An attacker could possibly use this issue to perform a timing
attack and recover the MIT cookie. (CVE-2017-2624)