We have a well appreciated update from the Dev-Team not long ago that a PDF Patch for the large security hole is being worked on by @saurik. The patch will fix the holes for all devices and all firmware versions going back as far as version 2.x. The package is currently in testing and will be release soon.
They also mention that there aren’t any malicious variants out yet, but they’re sure to come. The guys are working hard so be a bit patient.