The Dangers of Outsourcing Mobile Security

Two stories broke recently revealing vulnerabilities in the security infrastructure for Android and iOS respectively. While vastly different in their nature, both point to a fundamental lesson that the enterprise must learn – don’t rely on mobile device OEMs or mobile OSs for enterprise grade security – ensure you are in direct control of security for sensitive corporate information including encryption and access control.

Two separate yet significant approaches to compromising encryption on Android and iOS broke in the news recently. The Android vulnerability, discovered as a result of a compromised Bitcoin transaction, is most directly relevant to encryption. In short, the Android operating system does not properly seed the PRNG (pseudo-random number generator) used by the built-in cryptography APIs. Randomness is essential to ensure that (a) encryption keys cannot be guessed, and (b) an attacker cannot successfully guess the contents of intercepted, encrypted messages. In short, any app that relies on these vulnerable APIs for its essential encryption functions is flawed, including everything from Bitcoin to a vast array of enterprise-targeted mobile apps developed by third party and in-house developers.

On the iOS side, a group of researchers at Georgia Tech successfully submitted an app with malicious capabilities and intentions to the Apple App Store. What the researchers discovered is that the cornerstone of Apple’s App approval process is a static analysis of the app code. How does malware posted to the App Store implicate iOS encryption? Well, the link here is indirect – malware installed on a device can exploit an OS vulnerability to “jailbreak” the device; once “jailbroken” the OS can no longer be trusted, and an untrustworthy OS should not be used for encryption nor should it be trusted to report on its own health and safety when a device management solution tries to determine if it is “jailbroken” or not.

The wake-up call for the enterprise is not in the nature of these attacks themselves – it is in the remediation they require. Enterprises have become adept at managing security vulnerabilities with all of their major vendors, and IT understands that vulnerabilities are a fact of life. The key to vulnerability management is to act on them quickly and effectively once identified. Here we come to the core issue.

Employees access corporate systems with a broad variety of Android and iOS devices. IT can neither upgrade the operating system on Android nor can it influence which apps are admitted to the Apple App Store. IT’s only viable strategy for remediating vulnerabilities in the mobile ecosystem is to attempt to block access to corporate systems or to blacklist access to specific apps. Neither approach is attractive. Locking broad swaths of employees out of corporate systems is not a particularly productive answer. Similarly, attempting to maintain an accurate malware blacklist is destined for failure (see anti-virus).

IT’s best (and only) strategy in a mobile enterprise is to retain complete control of the components of the mobile software stack that matter most. Encryption and access control are the building blocks of the mobile security infrastructure, and the software implementing these two operations must be as firmly in IT’s control as is possible. In practice, this means that a software-only container, which includes its own full stack implementation of all cryptography functions and all secure network protocols (e.g., a full SSL/TLS stack), should be the only software trusted to handle sensitive corporate data and to authenticate corporate users. This strategy is not perfect because no software (including the container itself) is perfect, but it restores control to IT when vulnerabilities are discovered.

As IT quickly loses control of the endpoint devices that employees choose to access corporate systems and data, IT must consider carefully when and where it is essential to retain control and how to do so. When security really matters, a secure container approach is the only answer. The question from there is how to deliver a first class mobile experience while still retaining the protections that a software container affords. As without a rich and compelling user experience, users will be reluctant to take advantage of the mobile app irrespective of its level of security.

– Seth

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