Dan Kaminsky of DoxPara Research found the flaw half a year ago. Since then he's been working with people from all over the globe to analyse the flaw, come up with a way to patch it, and get the patches ready for everyone at once.
Dan Kaminsky will make the details of the vulnerability available 6 August 2008. This gives everyone time to patch the flaw. Fortunately the flaw is hard to trace even after the patch is applied so malware attacks should be held to an absolute minimum.
For the time being Kaminsky summarises the situation as follows.
After that you wait for Black Hat.
According to CERT the following systems are affected.
3com, Akamai, Alcatel, Apple, AT&T, Avaya, Avici, BlueCat, Check Point, Cisco, Conectiva, Cray, D-Link, Data Connection, Debian, DragonFly BSD, EMC, Engarde Secure Linux, Ericsson, Extreme Networks, F5 Networks, Fedora, Force10, Foundry Networks, FreeBSD, Fujitsu, Gentoo, Gnu ADNS, GNU glibc, Hewlett-Packard, Hitachi, Honeywell, IBM, IBM Z Series, IBM eServer, Infoblox, Ingrian, Intel, ISC, Juniper, Linux Kernel Archives, Lucent, Luminous, Mandriva, Men & Mice, Metasolv, Microsoft, MontaVista, Motorola, Multinet, Multitech, NEC, NetApp, NetBSD, Netgear, Network Appliance, Nixu, NLnet Labs, Nokia, Nominum Vulnerable, Nortel, Novell, OpenBSD, Openwall, PowerDNS, QNX, Red Hat, Redback, Shadowsupport, Siemens, SGI, Slackware, Sony, Sun, SUSE, SCO, Trustix, Turbolinux, Ubuntu, Wind River Systems, ZyXEL.
Applying port randomisation should be enough to thwart hack attempts for now and Kaminsky's online test checks precisely this capability.