Apple breaks it and jailbreakers fix it. It’s an exaggerated statement to say the least but Apple has let quite a few security bugs get by them, most notorious of which was the lock screen bug. The latest security flaw discovered in iOS 7 is that file attachments sent in emails using the default Mail app are not encrypted. The flaw has been acknowledged by Apple and a fix is on its way, blah blah blah. For users who have jailbroken their device though, the fix is here. AttachmentEncryptor is a tweak that encrypts those attachments. It has no interface, no buttons or switches to flip, nothing. It works silently in the background and fixes everything.
AttachmentEncryptor fixes the bug discovered by Andreas Kurtz. The tweak is available in the rpetrich repository and it is in beta but it does the job. Install it like any other tweak and you’re attachments are secure and protected.
Users who have not jaibroken their device or who can’t jailbreak because it isn’t available for the version of iOS that they are running will have to wait for a patch from Apple itself. It’s likely to come out soon, quite soon because the bug is indeed serious and Apple responded quickly enough with a patch for the lock screen bug which was also critical.