Google’s ClientLogin Application Programming Interface (API) has been found to be insecure by researchers from Germany’s University of Ulm.  This means that most Google Android phones leak temporary user authentication credentials called “AuthTokens” which are valid for 14 day periods.  The leak occurs because AuthTokens are transmitted without any encryption in Google Android prior to versions 2.3.4 or 3.x, and more than 99% of Android Phones (according to Google Statistics) run older vulnerable versions of Android.  It is unclear when those devices will be upgraded, if ever.  Furthermore, the fixed variants of Android still have problems authenticating securely with Google’s Picasa service.

If a user accesses Google Calendars or Contacts from their smartphone while accessing the Internet from any typical hotspot (which are almost never encrypted), hackers can gain access to the AuthToken.  Furthermore, the Android smartphones will automatically sync to these online services as soon as the hotspots are available which means the leakage is automatic and immediate.  Once the AuthToken is copied, hackers can access user data or impersonate the user.

Google was doing well in security when they were the only major online service to ace my online security reportcard, while services like Twitter and Facebook flunked.  Facebook and Twitter have somewhat fixed their shortcomings with opt-in security which users will rarely manually activate, but this latest problem for Google is even more difficult to solve because it require more than just a fix on the server end.  Every Android device will have to be upgraded to patched versions and that may take time to deploy, and some devices may never get fixed.

The only way to avoid this problem now is to completely avoid unencrypted Wi-Fi hotspots – but that is virtually all of them.  Wi-Fi is popular because it relies on wired broadband or Internet connections with lower latency and higher capacity.  Mobile 3G or 4G networks are secure because they have universally implemented link layer data encryption, so there is no known method for stealing data off the wireless network.