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. ()

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. (









.

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

,

CVE-2017-2624