Network File System (NFS) in FreeBSD 4.6.1 RELEASE-p7 and earlier, NetBSD 1.5.3 and earlier, and possibly other operating systems, allows remote attackers to cause a denial of service (hang) via an RPC message with a zero length payload, which causes NFS to reference a previous payload and enter an infinite loop.
https://exchange.xforce.ibmcloud.com/vulnerabilities/9772
http://www.securityfocus.com/bid/5402
http://www.info.apple.com/usen/security/security_updates.html