The issues arose from the way in which Ashley Madison handled photos designed to be hidden from public view. But Ashley Madison automatically shares a user's key with another person if the latter shares their key first. This makes it possible to sign up and start accessing private photos. Even those who aren't signed up to Ashley Madison can access the images by clicking the links. In their tests, the researchers gave a private key to a random sample of users who had private pictures.

Source: Forbes December 06, 2017 15:04 UTC