Web extra: Improving software security by shrinking its attack surface

Attack surface profiles look at all the entry and exit points in a program, such as the interfaces for exchanging data with other systems. "Anytime you interact with the [IT] environment, there's a way to leak information from inside the system to that environment," said Jeannette Wing, a computer science professor at the university and assistant director at the National Science Foundation's Computer and Information Science and Engineering Directorate.

Those application openings differ from the vulnerabilities created by software bugs, Wing said. Instead of being mistakes, they are practical components of applications. "They're all legitimate. It's just that any one of them could be exploited in an attack."

Wing's research will help identify future solutions by devising a program that makes an inventory of entry and exit points and systematically assesses the risk of each point. 

"In the grand scheme of things, we'd have software that you'd run to pore through the code and [determine] the privilege level needed to gain entry through these points," Wing said. "It turns out to be very, very difficult to do."

The research, which has been going on for four years, is nearing the prototype stage. Wing said a working version of the analysis tool could ultimately help software developers and agency IT managers decide how to plug software holes that provide data-theft opportunities for criminals and cyberterrorists. "Right now, IT managers don't have a lot of tools to help them make those kinds of decisions."