Washington (dpa) - Facebook on Thursday admitted to another privacy lapse affecting some of its users' passwords.
The social media company said the passwords had been stored in a readable format within its internal data storage systems and were visible to Facebook employees.
"This caught our attention because our login systems are designed to mask passwords using techniques that make them unreadable," Facebook said in a message to users.
The message said no passwords were exposed externally and no evidence of abuse was found.
The readable passwords were discovered as part of a routine security review in January. The problem has been fixed and Facebook will notify everyone whose passwords were affected.
That will amount to hundreds of millions of Facebook Lite users, tens of millions of other Facebook users, and tens of thousands of Instagram users, the company said.
Facebook Lite is a version used predominantly by people in regions with lower connectivity.
The company also has fixed problems in the ways it stores certain other categories of information.
"There is nothing more important to us than protecting people's information, and we will continue making improvements as part of our ongoing security efforts at Facebook," the company said.
Facebook's message comes one day after a website that covers security exposed the problem.
KrebsOnSecurity.com said the passwords were searchable by thousands of Facebook employees and some dated back to 2012.
The security lapse is the latest in a series of troubles for the company whose services are used by more 2 billion people around the world on average every day.
