By your own definition this tracks. They didn’t leave the data vulnerable on purpose, and it got accessed by someone who shouldn’t have seen it. And the environment was clearly not secure enough.
- A data breach occurs when data that is unintentionally left vulnerable in an unsecured environment is viewed by someone who shouldn't have access to that data.
This is a bit confused definition, because it can be both. Here it is very much human negligence (the credentials should have been disabled) combined with someone intentionally making use of the situation.
- A hack is the result of an intentional attack, while a breach is the result of human negligence.
Like the example here.
- A data breach is a more general term and simply refers to the outcome that data was made available to unauthorised people.
But really, this distinction is a red herring because a ‘hack’ is a particular scenario in which a data breach occurs. From GDPR art. 4 p. 12:
‘personal data breach’ means a breach of security leading to the accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to, personal data transmitted, stored or otherwise processed;