Although ominous-sounding terms like "zero-day" and "exploit" are widely used, even many security professionals don't know how bug hunters actually find and attack software security flaws. In A Bug Hunter's Diary, readers follow along with security expert Tobias Klein as he tracks down and exploits bugs in some of the world's most popular programs. Whether by browsing source code, poring over disassembly, or fuzzing live programs, readers get an over-the-shoulder glimpse into the world of a bug hunter as Klein unearths security flaws and uses them to take control of affected systems. Readers learn about critical vulnerabilities in Mac OS X, Linux, Oracle Solaris, and the iPhone OS, among others. They also learn how the developers responsible for these flaws responded to Klein's discoveriesor didn't seem to respond at all. In this one-of-a-kind guide that mixes the personal with the deeply technical, readers learn how hackers approach difficult problems, see the fallout of a security advisory, and understand the true joys (and frustrations) of bug hunting.