Isn't this already known by people who actually take security measures with their computers?
I've especially known this about Adobe acrobat and reader for quite a while. Usually it is Trojans that exploit via a fake update option and you unknowingly download the nasty Trojan.
*waits for Shayd to come and explain further and put our minds at ease*
But you're right that's one of the major issues. There are also hundreds of liabilities where memory leaks are concerned, as a number of hackers have shown at conferences that they can use buffer overflows to essentially take control of the program and to a certain degree the infected computer.
But then again, who uses Adobe Reader? I've used FoxIt Reader for 5 plus years, it's a lot smaller, more secure, and doesn't take 14 years to open a single PDF.