GNUnet before SVN revision 2781 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via an empty UDP datagram, possibly involving FIONREAD errors.
https://gnunet.org/svn/GNUnet/ChangeLog
https://exchange.xforce.ibmcloud.com/vulnerabilities/26527
http://www.vupen.com/english/advisories/2006/1799
http://www.securityfocus.com/bid/17980
http://www.securityfocus.com/archive/1/433933/100/0/threaded
http://securityreason.com/securityalert/907