The remote host is missing an update to vino announced via advisory DSA 2238-1.
Kevin Chen discovered that incorrect processing of framebuffer requests in the Vino VNC server could lead to denial of service. For the stable distribution (squeeze), this problem has been fixed in version 2.28.2-2+squeeze1. For the unstable distribution (sid), this problem has been fixed in version 2.28.2-3. We recommend that you upgrade your vino packages.