Google is once again boosting the maximum bounty payouts for Linux vulnerabilities reported as part of its open-source Kubernetes-based capture-the-flag (CTF) vulnerability rewards program (VRP).
Called kCTF, the program was launched in 2020 to provide security researchers with the means to report vulnerabilities in the Google Kubernetes Engine (GKE), for which they receive a flag.
“All of GKE and its dependencies are in scope, but every flag caught so far has been a container breakout through a Linux kernel vulnerability. We’ve learned that finding and exploiting heap memory corruption vulnerabilities in the Linux kernel could be made a lot harder,” Google notes.
To that end, the internet giant has introduced a new set of mitigations expected to make most of the previously reported vulnerabilities and exploits more difficult to use in attacks.
Google introduced these mitigations to fight against out-of-bounds writes on slab, cross-cache attacks, elastic objects, and freelist corruption.
In an effort to incentivize security researchers to discover ways to break those mitigations, Google is also announcing bonus rewards for vulnerabilities in the latest Linux kernel and for bypassing the newly introduced mitigations.
Each of these two bonuses is of $21,000 and together they enable security researchers to earn as much as $133,337 for critical vulnerabilities reported as part of kCTF.
The new bonus rewards come half a year after Google almost doubled the base bounty payouts in kCTF and announced high bonuses for specific vulnerabilities. With three $20,000 bonus rewards on top of the $31,337 base reward, researchers could earn $91,337 for exploits meeting certain criteria.
Now, the company says it is indefinitely extending the increased reward amounts that it announced last year, to which it also adds the new $21,000 bonuses.
“We hope this will allow us to learn more about how hard (or easy) it is to bypass our experimental mitigations,” Google notes.