This paper has been published at the USENIX LISA 2002 conference <http://www.usenix.org/events/lisa02/>, and is available for download here <http://wirex.com/%7Ecrispin/time-to-patch-usenix-lisa02.ps.gz>. Timing the Application of Security Patches for Optimal Uptime Steve Beattie, Seth Arnold, Crispin Cowan, Perry Wagle, and Chris Wright WireX Communications, Inc. http://wirex.com and Adam Shostack Informed Security http://www.informedsecurity.com Security vulnerabilities are discovered, become publicly known, get exploited by attackers, and patches come out. When should one apply security patches? Patch too soon, and you may suffer from instability induced by bugs in the patches. Patch too late, and you get hacked by attackers exploiting the vulnerability. We explore the factors affecting when it is best to apply security patches, providing both mathematical models of the factors affecting when to patch, and collecting empirical data to give the model practical value. We conclude with a model that we hope will help provide a formal foundation for when the practitioner should apply security updates. Crispin -- Crispin Cowan, Ph.D. Chief Scientist, WireX http://wirex.com/~crispin/ Security Hardened Linux Distribution: http://immunix.org Available for purchase: http://wirex.com/Products/Immunix/purchase.html Just say ".Nyet"
