Apple has released a free software update that corrects a security flaw in the iPhone, a day after a researcher demonstrated the problem at a conference.
"No one has been able to take control of the iPhone to gain access to personal information," said Apple spokesman Tom Neumayr.
The vulnerability could have let malicious code into the phone through text messages.
Charlie Miller, an analyst with Independent Security Evaluators, pointed out the flaw at the Black Hat security conference in Las Vegas. Hackers can use the iPhone's software and mobile-phone systems from Google and Microsoft to send texts via SMS, he said.
They then could take over the phone or cause it to crash, Mr Miller said.
Mr Miller and Collin Mulliner, a PhD student at the Technical University of Berlin, also discovered a method that allow hackers to easily knock a victim's iPhone off a carrier's network.
It would prevent users from making calls, accessing the Internet and exchanging text messages, they added.
They said the information they presented at Black Hat will give criminals enough information to develop software to break into iPhones within about two weeks.
They said they warned Apple of the flaw in the middle of July.
About 4,000 security professionals were in attendance at the Nlack Hat conference, including some who are really hackers. While experts ferret out software flaws to fix them and protect users, hackers use the same information to devise pranks or commit crimes.
The researchers showed the audience how to break into iPhones by sending computer code via the phone's SMS system. Mobile phones use SMS to send and receive text messages along with software upgrades. They said that the phone's users cannot detect that it is receiving the malicious code.
It is not illegal to disclose ways to hack into computer systems, though it is against the law to use it to break into them.
When asked why they would hand over such information to criminals, security experts said they felt it was necessary to alert the public that iPhones were just as vulnerable to attack as personal computers.
"If we don't talk about it, somebody is going to do it silently. The bad guys are going to do it no matter what," Mulliner said.
They have successfully tested the hacks on iPhones running on networks of four carriers in Germany along with AT&aT in the United States. They said they believed the methods will work with iPhone carriers around the world.
The two said they used a similar method to break into phones running on Google's Android operating system. Google patched the flaw after they notified the company of the vulnerability.
Bloomberg/Reuters