Chris Evans discovered that the GStreamer 0.10 plugin to decode NES Sound Format files allowed the execution of arbitrary code. Further details can be found in his advisory at <http://scarybeastsecurity.blogspot.de/2016/11/0day-exploit-compromising-linux-desktop.html>.
For the stable distribution (jessie), this problem has been fixed in version 0.10.23-7.4+deb8u1.
The unstable distribution (sid) no longer contains Gstreamer 0.10.
We recommend that you upgrade your gst-plugins-bad0.10 packages.