If you have and iOS device (iPhone or iPad) running iOS 7 and haven’t updated to 7.0.6… do it. RIGHT NOW. Don’t finish your chips. Don’t wait for the movie to end. Don’t wait until you work things out with your receptionist. Update it RIGHT NOW.
To update your device: Tap Settings > General > Software Update > Download and Install.
If you don’t know what version you’re running, tap Settings > General > About. Check ‘Version’. If it’s 7.0.x and NOT 7.0.6, update.
EDIT:
So it seems that the claim is that it only affects ‘Mavericks’ (OS X 10.9) but could affect older versions as well. Furthermore, in “…OS X, the flaw is likewise limited to SSL connections over unsecured Wi-Fi networks, though only in Safari”. What this means is that if you are using Safari on 10.9 on public WiFi that has no encryption (did you enter a password to connect? If not, it’s unencrypted), you’re potentially at risk.