The passwords of hundreds of millions of Facebook users were stored in plain text and searchable by thousands of Facebook employees for years, according to a report by KrebsOnSecurity.

According to the report, Facebook is probing a series of security failures in which employees built applications that logged unencrypted passwords and stored them in plain text on internal company servers. It said that according to a source:

  • The investigation so far indicates between 200 million and 600 million users may have had their passwords stored in plain text and searchable by more than 20,000 Facebook employees
  • Facebook is still trying to determine how many passwords were exposed and for how long, but so far the inquiry has uncovered archives with plain text user passwords dating back to 2012.

KrebsOnSecurity said it spoke to a Facebook insider who said access logs showed around 2,000 engineers or developers made approximately nine million internal queries for data elements that contained plain text user passwords.

No evidence so far that data was misused, says Facebook

In response to the report, Pedro Canahuati, VP engineering, security and privacy at Facebook, issued the following statement: “As part of a routine security review in January, we found that some user passwords were being stored in a readable format within our internal data storage systems. We have fixed these issues and as a precaution we will be notifying everyone whose passwords we have found were stored in this way.

“To be clear, these passwords were never visible to anyone outside of Facebook and we have found no evidence to date that anyone internally abused or improperly accessed them. We estimate that we will notify hundreds of millions of Facebook Lite users, tens of millions of other Facebook users, and tens of thousands of Instagram users.”

Securing your account

Facebook’s statement also included the following advice on choosing a password and securing your account:

“Here are some steps you can take to keep your account secure:

  • You can change your password in your settings on Facebook and Instagram. Avoid reusing passwords across different services.
  • Pick strong and complex passwords for all your accounts. Password manager apps can help.
  • Consider enabling a security key or two-factor authentication to protect your Facebook account using codes from a third party authentication app. When you log in with your password, we will ask for a security code or to tap your security key to verify that it is you.”

Cambridge Analytica scandal

This is Facebook’s biggest privacy scandal since early 2018, when it was revealed that political consulting firm Cambridge Analytica had harvested the personal data of millions of people’s Facebook profiles without their consent and used it for political purposes in the US Presidential election. The controversy precipitated a massive fall in Facebook’s stock price and calls for tighter regulation of tech companies’ use of data. Facebook CEO Mark Zuckerberg was called to testify before the US Congress on April 10, 2018, and said, “It was my mistake, and I’m sorry. I started Facebook, I run it, and I’m responsible for what happens here.”