Google then noted how the site wasn't really becoming a strong social destination, despite the fact that it could link up with other pages such as Gmail, Blogger and YouTube.
Ben Smith, Google's vice president of engineering, confirmed in a blog post the company had detected a "bug" in March that impacted the profiles of as many as 500,000 Google Plus users.
According to the paper, the memo said that while Google could not find evidence that the exposed data had been misused, it also could not prove that misuse did not happen.
Google has been moving away from Google+ for a while, with the company launching new features for its core search engine where popular individuals, like celebrities, are able to directly post updates within search results.
The Google+ flaw could have allowed 438 external apps to scoop up user names, email addresses, occupations, gender and age without authorization.
The company decided not to disclose the breach "because of fears that doing so would draw regulatory scrutiny and cause reputational damage", the WSJ reports.
"I think Google does have a public relationship issue and this now makes their lack of openness even worse", Ivan Feinseth, an analyst at Tigress Financial Partners said. The bug was patched in March 2018, but only detailed now.
Finding 1: There are significant challenges in creating and maintaining a successful Google+ product that meets consumers' expectations. Google has also revealed details of Project Strobe, an audit program through which it discovered the problem.
Google will take the next 10 months to kill off G+ for consumers, finishing it off by August of 2019.
Action 4: We are limiting apps' ability to receive Call Log and SMS permissions on Android devices, and are no longer making contact interaction data available via the Android Contacts API.
Many have long suspected that Google+ was in its final days, but nearly no-one could have predicted it would end like this.
Google has recently been at the center of a number of privacy breaches. Google account permissions will have more granular controls for each permission an app requests (see above). The company was the target of a massive class action lawsuit in the United Kingdom after 4 million users had their personal data collected and allegedly used for targeted advertising.
The news adds to Google's woes and further erodes the narrative that Facebook is the worst offender of the major technology companies on data privacy.