Millions of mobile phones across the world could have their security threatened as an expert from Germany claims to have found a SIM card vulnerability.
Karsten Nohl, founder of Security Research Labs in Berlin, explained to the New York Times that the encryption hole meant that hackers could gain access to a SIM card's digital key.
With this information, it is possible to send a virus to the SIM card in the form of a text message, therefore putting mobile application security at risk.
He noted: "We can spy on you. We know your encryption keys for calls. We can read your SMS.
"More than just spying, we can steal data from the SIM card, your mobile identity, and charge to your account."
The operation was completed in around two minutes with the aid of just a simple computer, suggesting that mobile users across the globe could be under threat.
Google recently made a new patch available to address a security flaw in Android devices, which it believed left 900 million smartphones and tablets open to hackers.
The flaw has existed at least since the release of Android 1.6 and is estimated to have affected 90 per cent of devices that are currently in circulation.