Windows NT 4.0 before SP3 allows remote attackers to bypass firewall restrictions or cause a denial of service (crash) by sending improperly fragmented IP packets without the first fragment, which the TCP/IP stack incorrectly reassembles into a valid session.

BUGTRAQ:19970710 A New Fragmentation Attack | URL:http://www.securityfocus.com/archive/1/7219 | XF:nt-frag(528) | URL:https://exchange.xforce.ibmcloud.com/vulnerabilities/528