The Federal Bureau of Investigation doesn’t plan to tell Apple Inc. how it cracked a San Bernardino, Calif., terrorist’s phone, said people familiar with the matter, leaving the company in the dark on a security vulnerability on some iPhone models.

The FBI knows how to use the phone-hacking tool it bought to open the iPhone 5c but doesn’t specifically knows how it works, allowing the tool to avoid a White House review, the people said, The FBI plans to notify the White House of this conclusion in the coming days, they added.

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