Linux, like every other networkable OS, is vulnerable to a variety of local and remote attacks. Hacking Linux Exposed seeks to do two jobs: explain where the vulnerabilities lie and provide ways to minimise or eliminate the risks. The authors" slightly breathless hands-on approach--coupled with the wealth of relevant technical detail--produces an unusually pacey read. Much of the spiciness comes from the emphasis on exploiting Linux"s weaknesses. This is helped with lots of case studies of successful intrusions. You won"t be in any doubt that you should be taking security seriously. Much of the advice is common sense: use secure passwords, shadow password files, turn off unwanted services, set up an efficient firewall, apply security patches and so on. But the devil is in the detail. Successfully hardening a Linux system is non-trivial (as with other OS"s). It"s also an ongoing process. What really sets Hacking Linux Exposed apart is the way it walks you through each vulnerability and then explains the technical aspects of implementing a defense against it--converting to shadow password files, setting up IPChains, automating log file checking, testing your own security and more are all detailed. Linux sysadmins will love this book. However, any Linux user with the confidence to edit a configuration file and a copy of Hacking Linux Exposed to hand can also have the hardest machine on the block. --Steve Patient