Apple disables jailbreak detection API in iOS 4.2.1
The API was originally bundled into iOS 4.0 and gave Apple and third party vendors the ability to detect jailbreaks by finding changes to the iOS system software. According to the report, Apple has not provided a reason for the API to be disabled, but vendors can utilize other methods to detect modifications to iOS.
Jailbreaking is mostly known for allowing users to install unofficial software and carrier unlocks onto their iPhone, iPod touch, and iPad. Network World suggests that jailbroken devices can be a threat to enterprise security since there is a possibility that malware could be present in unauthorized apps.