Paying rewards to independent security researchers for finding
software problems is a vastly better investment than hiring employees to
do the same work, according to researchers from the University of
looked at vulnerability reward programs (VRPs) run by Google and Mozilla for the Chrome and Firefox web browsers.
Over the last three years, Google has paid $580,000 in rewards, and
Mozilla has paid $570,000. In the course of those programs, hundreds of
vulnerabilities have been fixed in the widely used products.
The programs are very cost effective. Since a North American
developer’s salary will cost a company about $100,000 with a 50 percent
overhead, “we see that the cost of either of these VRPs is comparable to
the cost of just one member of the browser security team,” the
Additionally, more eyes on the code meant the VRPs uncovered many more software flaws than just one hired developer could find.
The study provides a sound foundation for reward programs, which are
not embraced by all vendors. Adobe Systems and Oracle do not pay for
Microsoft has traditionally not paid bounties, but did implement a
one-off program last month. Through July 26, Microsoft will pay up to
$11,000 for bugs in its Internet Explorer 11 browser.
Bug bounties have other advantages, such as by reducing the number of
vulnerabilities that are sold to malicious actors who would use the
information for criminal activity. The programs also make it harder for
hackers to find vulnerabilities, the researchers wrote.
But a key difference between Google’s and Mozilla’s programs may affect their effectiveness.
Mozilla pays a flat $3,000 reward for a vulnerability. Google pays on
a sliding scale, which ranges from $500 to $10,000. Google judges
vulnerabilities and exploits on factors such as difficulty and impact.
Google’s average payout is just $1,000, but the chance of obtaining a
much higher reward appears to provide an incentive for more people to
participate in its program, the researchers wrote.
Google’s program, while costing about the same as Mozilla’s, “has
identified more than three times as many bugs, is more popular and shows
similar participation from repeat and first-time participants.”
“This makes sense with an understanding of incentives in lotteries:
the larger the potential prize amount, the more willing participants are
to accept a lower expected return, which, for VRPs, means the program
can expect more participants,” according to the paper.
Also, browser penetration contests such as “Pwnium” run by Google
with rewards up to $150,000 sparks more interest among researchers.
“We believe this sort of ‘gamification’ leads to a higher profile for
the Chrome VRP, which may help encourage participation, particularly
from researchers interested in wider recognition,” the paper said.
“Accordingly, we recommend Mozilla change their reward structure to a tiered system like that of Chrome,” it said.
The paper was authored by Matthew Finifter, Devdatta Akhawe and David Wagner.