There has never been more focus on security than there is right now. Researchers say that, for a variety of reasons, it has become increasingly difficult to find exploitable client-side bugs. The DLL-hijacking flaw, the recent LNK bug and even the iPhone bugs used in the Jailbreakme.com incident are examples of this trend. Security researchers say the job of finding exploitable bugs more challenging than ever, researchers say. This is not how it used to be, for most of the last decade.
Source: https://threatpost.com/easily-exploitable-bugs-becoming-precious-commodity-090110/74410/