Returning from CanSecWest left me reflecting on how the Pwn2Own competition has evolved over time. A lot has changed in the Pwn2Own competition over the years. The event has grown in attendance, competitors, and complexity, just as the industry has grown.
For the first contest in 2007, no one competed on the first day. Shane McCauley called fellow security researcher Dino Dai Zovi in NYC that night and urged him to compete. Dino was able to write the exploit over night and win the contest on the second day. Visually, the attacks seem no different from year to year. The contestant sits down at the machine, and “seconds” later the calculator (or notepad in this year’s case), pops up on the screen. However, the preparation for the attacks from 2007 to 2016 are now drastically different, with contestants preparing attacks weeks in advance.
Media coverage around security advisories is often just a run down of how many CVEs a vendor released that month. People often imply from these articles that all the CVEs are easily exploitable and trivially weaponizable. This can lead to false perceptions that exploiting the software is a simple task. In reality, a CVE from a vendor is not a guarantee of exploitability. Even if the CVE can give the attacker the ability to overwrite memory, that is not a guarantee that it can be weaponized. Technologies such as ASLR (Address Space Layout Randomization) weren’t even released for Mac OS X when Dai Zovi competed in 2007. Today’s attackers have to work around defenses such as CFG (Control Flow Guard), Isolated Heaps, and a number of other technologies designed to prevent a crash from becoming an exploit.
In addition, competitors have to deal with the fact that the contest frequently occurs after Patch Tuesday where a vendor’s security improvements could interfere with their attack. Adobe has been aggressively adding mitigations to Flash Player over the last few months. In our release the week before the contest, we added changes to zero memory more often and leveraged the Windows’ low fragmentation heap. Both Adobe and Google found that some of the contestant’s entries overlapped with recent security reports. Part of the reason for the increasing payouts for the winners comes from the fact that the targets for the competition all have active security teams and external communities that are constantly working to improve the platform. As the community and vendors continue to mature their software, bug or mitigation collisions become more of a material risk for competitors. While it may not seem like it on the surface, the attackers are trying to hit moving targets.
The Flash Player updates prior to the contest led to some failed attempts at the competition. The failed attempts were by teams who had already won under different categories. Therefore, the competitors were clearly highly skilled and had already proven themselves to be capable of weaponizing exploits for the target platform. The reality is that what they are attempting to do is not easy and the failures serve to remind us how hard it is to get those wins. When any competition gets to a certain level, even the most skilled players are going to experience some losses.
That said, the contest always has its share of winners. Those wins demonstrate that there is always more that vendors can do in order to improve security. While the individual bugs help, Pwn2Own is truly valuable because it shows how different researchers will try to bypass the existing mitigations to create the fully weaponized exploit. That insight into different attack approaches inspires us as vendors to come up with the next generation of defenses.
Like many pros, the winning contestants always make it look easy. Although, as an industry we are often too quick to lump everything in the same “it is easy because it is completely vulnerable” bucket. Companies like Adobe, Microsoft, and Google are in a constant sprint with attackers. The security industry has progressed from the days of just trying to write clean, well validated code. Today, we are adding in large platform features that serve no other purpose than trying to thwart attackers. These types of features are added at an increasingly frequent basis. The companies who are on the front line of this battle will change and grow over time. It is important for those vying to one day be on the defender’s side of Pwn2Own to understand the current table stakes.
Overall, Pwn2Own is a fun contest to interact with security researchers and to push the industry forward. Beneath the high level pageantry of smoking jackets and large prizes, is a low-level escalation between offensive and defensive strategists. While the visual results from watching in the room seem similar from year to year, the innovation and challenge required to achieve those results increases every year.