Three weeks ago Path.com was fined for stupidly stealing their user’s contact list and saving it onto their servers. Path’s doing was obviously wrong but I’m not sure that their punishment was really justified, needing to pay this enormous bribe to the FTC using COPPA as an excuse. The lesson here is to always comply with COPPA.
Anyhow, in that same techcrunch article you can also find that “The FTC also took the opportunity to introduce a new set of guidelines for mobile developers“. Although they explain early in that article that it’s not meant to be a guideline, I still feel they misses a lot.
How will that code be injected you may ask – all that is needed is for the app to load some content from a remote server the simplest example will be the “Terms And Condition” page which is mostly loaded into a WebView. It can be a more “complex” settings, like choosing the favorite color or loading the saved alarms. Any kind of sharing will probably be way more open to be exploited, i.e. “share your favorite alarms”. Push messages might also bring malicious code. ETC’
Things like stealing the user’s contact list and tracking the user location are pretty common. Enabled by default in iPhone PhoneGap for example.
As opposed to that, it’ll take a very special case for injection to be able to execute arbitrary native code. You can make a native android app that will run anything – even get root, but I doubt that any legitimate app regularly download strings and run it as commands. (basically on rooted Android you can do exec(“su”) and everything else)
These kind of injection are not the sole problem of PhoneGap based applications.
Phonegap (Cordova) has a mechanism to white list remote hosts which is really only effective on the iOS. It adds a little bit of security, but many apps anyway uses a wildecard “*” to allow all hosts. The wildcard is used by default in the phonegap cloud (saas solution to build phonegap apps)
As you can see the option for an attacker are enourmoe, all it needs is one vector of injection and there is an open path (no phan) to take over all of the devices of all of the users.
HTML5 apps that runs inside the mobile browser are also a nice target for injection attacks, althouygh it’s lacking most of the native api, there is still access to location in all mobile browsers. It’s less powerful for the attacker since it’ll prompt the user way more vigusly.
The Dolphin Mobile Browser implement the full phonegap native api, for example (which is generally a good thing), but it makes in-the-browser websites and apps more exposed to attacks.
So what to do than?!
- Sanitize sanitize sanitize all user input, server and client!