Michael Santo of RealTechNews writes:
Patch one thing and boom! here comes another issue. Not only that the fault lies not in a bug or flaw in the code; it was designed this way. Details were released at the ShmooCon hacker conference in Washington, D.C. on Saturday. Brian Krebs of the Washington Post has the full details here.
It’s a pretty detailed explanation of the problem. A somewhat simplified look at it can be found here.