Apple today released a rebuttal to the security vulnerabilities that Google detailed in depth last week and called it “one of the largest attacks against iPhone users ever.” The iOS maker took issue with several key points, but Google is standing by its works.

Google’s Project Zero often discovers flaws in the software of other companies and gives 90 days for those flaws to be fixed before revealing them to the public. Today, Google has taken the wraps off of a flaw with Apple’s iMessage which would cause iPhones to repeatedly crash. Thankfully, Apple has already fixed it.

Google’s Project Zero team is well-known for revealing the bugs and security flaws within systems from Google itself, as well as other big companies. Most recently, the team at Google has reported and publicly disclosed a “high severity” flaw in the macOS kernel which can grant an attacker access to a users computer without their knowledge.