(RHSA-2015:2233) Moderate: tigervnc security, bug fix, and enhancement update

Virtual Network Computing (VNC) is a remote display system which allows
users to view a computing desktop environment not only on the machine where
it is running, but from anywhere on the Internet and from a wide variety of
machine architectures. TigerVNC is a suite of VNC servers and clients.
The tigervnc packages contain a client which allows users to connect to
other desktops running a VNC server.

An integer overflow flaw, leading to a heap-based buffer overflow, was
found in the way TigerVNC handled screen sizes. A malicious VNC server
could use this flaw to cause a client to crash or, potentially, execute
arbitrary code on the client. (CVE-2014-8240)

A NULL pointer dereference flaw was found in TigerVNC’s XRegion.
A malicious VNC server could use this flaw to cause a client to crash.
(CVE-2014-8241)

The tigervnc packages have been upgraded to upstream version 1.3.1, which
provides a number of bug fixes and enhancements over the previous version.
(BZ#1199453)

This update also fixes the following bug:

• The position of the mouse cursor in the VNC session was not correctly
  communicated to the VNC viewer, resulting in cursor misplacement.
  The method of displaying the remote cursor has been changed, and cursor
  movements on the VNC server are now accurately reflected on the VNC client.
  (BZ#1100661)

All tigervnc users are advised to upgrade to these updated packages, which
correct these issues and add these enhancements.