The modern style negotiation in Network Block Device (nbd-server) 2.9.22 through 3.3 allows remote attackers to cause a denial of service (root process termination) by (1) closing the connection during negotiation or (2) specifying a name for a non-existent export.
lists.opensuse.org/opensuse-updates/2015-06/msg00003.html
sourceforge.net/p/nbd/mailman/message/30410146/
www.debian.org/security/2015/dsa-3271
www.openwall.com/lists/oss-security/2015/05/19/6
www.openwall.com/lists/oss-security/2015/05/21/5
www.securityfocus.com/bid/74808
www.ubuntu.com/usn/USN-2676-1
bugs.debian.org/cgi-bin/bugreport.cgi?bug=781547
github.com/yoe/nbd/commit/741495cb08503fd32a9d22648e63b64390c601f4