If you needed a reason to upgrade to a more current version of iOS, here's one: a group of Johns Hopkins University researchers found a bug that allows an attacker to decrypt photos and videos sent via iMessage on older versions of iOS.

Apple devices running a version of iOS 8 or earlier are most at risk. Apple partially patched the problem with last year's release of iOS 9, a modified exploit could be developed for more up-to-date gadgets. So upgrading to iOS 9.3 when it arrives is a must.

As reported by The Washington Post, researchers wrote software to mimic an Apple server, intercepted files, then "brute forced" their way past an encrypted 64-bit key to nab photos and videos sent via iMessage.

"Apple works hard to make our software more secure with every release. We appreciate the team of researchers that identified this bug and brought it to our attention so we could patch the vulnerability," Apple said in a statement. "Security improvements in iOS 9.0 blocked external attackers from performing the message intercept necessary to perform the attack identified in this report. Further targeted protections have been added in the beta version of iOS 9.3 and will be included in the public release for all users. Security requires constant dedication and we're grateful to have a community of developers and researchers who help us stay ahead."

Apple is expected to release iOS 9.3 at its "Loop You In" event this afternoon. Green urged all iDevice owners to update to iOS 9.3 as soon as possible.

According to the Post, this bug likely would not have been much help to the FBI in its bid to unlock the phone of the San Bernardino shooter. For one thing, Green's team was "focused on intercepting data in transit between devices," the newspaper said, while the feds want to crack a physical phone. But the main point they want to drive home is that cracking Apple's encryption is not impossible.