Following last weeks news of the Android system "Master Key" vulnerability and yesterday's update that Google has released a patch which it already distributed to its OEMs, Bluebox Security, which discovered the master key vulnerability, has now released Bluebox Security Scanner; an app which allows users to directly check if an Android device has been patched. Furthermore, the utility also does a partial device integrity check by searching for malicious apps leveraging the "master key" vulnerability. If your device has not been patched, it will provide you with the information you need to ask your device manufacturer when a fix will be available.
On a side note, it seems that - even if it wasn't said in yesterdays news - HTC has already patched the security hole with its latest release of Android 4.2.2 for the HTC One. After I did the scan on a recently upgraded 4.2.2 One, the scanner reported "Patch Status Patched" (click here for a screenshot). Definitely good news and it shows that the OEMs are already actively working on fixes. More patches are expected to be released soon.
In the meantime you might want to download the free Bluebox Security Scanner from either Google Play or Amazon Appstore.
Cheers ~ Arne