Researchers found an issue with an iPhone call recording app, which boasts of more than 1,000,000 downloads Researchers used various security testing tools to view and modify network traffic used by the app. From there, they discovered it was possible to replace their own phone number with someone elses. With that done, recordings from that phone (located in the cloud, on an Amazon AWS bucket) were available to them, without a password. The entire call history and the numbers calls were also available, at least until the app was updated and the problem fixed by the developers.”]
Source: https://blog.malwarebytes.com/privacy-2/2021/03/iphone-app-exposed-other-peoples-call-recordings/