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Ubuntu Security Notice USN-3171-1
January 11, 2017

libvncserver vulnerabilities
===========================================================================

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

- Ubuntu 16.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in LibVNCServer.

Software Description:
- libvncserver: vnc server library

Details:

Josef Gajdusek discovered that the LibVNCServer client library incorrectly
handled certain FrameBufferUpdate messages.  If a user were tricked into
connecting to a malicious server, an attacker could use this issue to cause
a denial of service, or possibly execute arbitrary code. (CVE-2016-9941,
CVE-2016-9942)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.10:
  libvncclient1                   0.9.10+dfsg-3ubuntu0.16.10.1
  libvncserver1                   0.9.10+dfsg-3ubuntu0.16.10.1

Ubuntu 16.04 LTS:
  libvncclient1                   0.9.10+dfsg-3ubuntu0.16.04.1
  libvncserver1                   0.9.10+dfsg-3ubuntu0.16.04.1

Ubuntu 14.04 LTS:
  libvncserver0                   0.9.9+dfsg-1ubuntu1.2

Ubuntu 12.04 LTS:
  libvncserver0                   0.9.8.2-2ubuntu1.2

In general, a standard system update will make all the necessary changes.

References:
  http://www.ubuntu.com/usn/usn-3171-1
  CVE-2016-9941, CVE-2016-9942

Package Information:
  https://launchpad.net/ubuntu/+source/libvncserver/0.9.10+dfsg-3ubuntu0.16.10.1
  https://launchpad.net/ubuntu/+source/libvncserver/0.9.10+dfsg-3ubuntu0.16.04.1
  https://launchpad.net/ubuntu/+source/libvncserver/0.9.9+dfsg-1ubuntu1.2
  https://launchpad.net/ubuntu/+source/libvncserver/0.9.8.2-2ubuntu1.2