If you manage Bitcoins through Android devices, you may need to keep a close eye on your virtual cash in the near future. Developers have found that multiple Android-based Bitcoin apps, such as Bitcoin Wallet and Mycelium Wallet, are vulnerable to number generator exploits that could be used for theft. Although patched apps are either available in beta or coming soon, the complete fix involves more than just new code -- users have to both create a new Bitcoin address and send it out to anyone still relying on old details. You're safe if you use a simple Bitcoin exchange client, but you'll otherwise want to visit the source link for more help with securing your digital holdings.
Update: A few days later, Google's Android security team has outlined the exact vulnerability. Apps that use Android's Java Cryptography Architecture sometimes don't get strong-enough encrypted values due to a bug. That's being patched at the OS level, but app writers can offer their own fix in the meantime.