When he's not at school, 15-year-old Cim Stordal spends his time playing the Team Fortress video game, shooting his Airsoft pellet gun, and working in a fish shop in Bergen, Norway. But his real passion is finding bugs in software used by millions of people on the Internet.
Stordal has made the Google Security Hall of Fame, been credited with disclosing a cross-site scripting bug to Apple, been thanked by Microsoft for disclosing a vulnerability to the company, and received an card from Facebook with $500 credit on it.
"I got a card for a self-persistent XSS [cross-site scripting flaw] at Facebook, and a nonpersistent XSS at Google, Microsoft, and Apple," he said in a recent Skype interview with CNET. (As a "self-persistent" issue, the bug Stordal disclosed was not exploitable by a third-party because it required a user to take an action to be at risk, according to Facebook.)
"I just look around at the site and find out where I can input HTML and stuff and it's not filtered in the source code. Often they filter some characters but forget some or they totally forget that input," he said. "What an attacker wants is often the cookie, which can be used to log-in as the user."
Stordal says of the sites he poked around in, Apple was the easiest to find a flaw in. "I found the Facebook [hole] after four days and the Google one after three, but Apple took me only five minutes" to find two XSS flaws, he said. (Apple representatives did not respond to a request seeking comment.)
The companies appreciate his efforts, particularly because he tells them before going public with any of the details. "Everyone was happy about it and fixed the flaws kind of fast."
Stordal started looking for vulnerabilities in software when he was 14 years old. "I have always loved being on the PC and I already was programming some C++," he said. "So I wanted to do something new and I searched around and learned Basic."
His friends are impressed with his skills and lean on him to help keep their Web sites secure. His parents aren't really sure what to make of his research.
"They think it's kind of cool, I guess, as they don't understand what I do," he said. "But they also don't want me to stay on the computer all day."
His next move is looking for vulnerabilities on mobile devices. He's trying to set up a fuzzer (automated software testing tool) on his iPhone 3GS.