I would like to protect my application data in case of any OS attack or unauthorized access on jail broken iOS devices. Is there any way to detect such threats and protect app data in such cases.
Although I agree with what jrturton has said, if you have critical data that you want to protect from rogue apps(not the user), you may try the following:
1) Detect if your app has launced on a jailbroken device. Close the app, delete sensitive data. Refer this this thread.
2)Use third party solutions like one from EnsureIT. They are somewhat helpful in saving critical data stored by an app, from a rogue user/app on a jailbroken device.
3) Try Obfuscating your code. More information on this link.
You may also find something useful from discussion in this thread