Rene Engelhard uploaded new packages for libreoffice which fixed the
following security problems:

   Use-After-Free in socket manager of Impress Remote

   It was discovered that LibreOffice 4.0.0 and later does not manage the port
   1599 for the LibreOffice Impress correctly. An external attackers with
   access to that port could cause the deleted port manager to continue to
   process attacker supplied data.

Note that this update also disables the remote contol per default as it
listens on port 1599 "to the world" per default. If you want/need it you
need to enable it manally:
   1. Open LibreOffice, go to "Tools -> Options..."
   2. Select "LibreOffice Impress -> General"
   3. Check "Presentation -> Enable remote control"

For the wheezy-backports distribution the problems have been fixed in
version 1:4.3.3~rc2-1~bpo70+1.