Apple may patch serious SMS vulnerability on iPhone

The iPhone is more secure than MacOS X-based computers, but SMS may be a critical weakness

Apple may be working to fix an iPhone vulnerability that could possibly allow an attacker to remotely install and run unsigned software code with root access to the phone.

The theoretical attack in question exploits a weakness in the way iPhones handle text messages received via SMS (Short Message Service), said security researcher Charlie Miller, during a presentation at the SyScan conference in Singapore on Thursday. He didn't provide a detailed technical description of the SMS vulnerability.

Miller is an authority on MacOS X security, and is a co-author of The Mac Hacker's Handbook.

An SMS flaw might allow an attacker to run software code on the phone that is sent by SMS over a mobile operator's network. In Miller’s case, it appears he used the flaw he found to remotely crash an iPhone, a sign that a more serious attack might be possible.

If so, the malicious code could theoretically include commands to monitor the location of the phone using GPS, turn on the phone's microphone to eavesdrop on conversations, or make the phone join a distributed denial of service attack or a botnet, Miller said

Miller reported the vulnerability to Apple, hoping it will get fixed. He plans to discuss the flaw further during a presentation at the Black Hat USA conference in Las Vegas.

Despite the SMS vulnerability, the stripped-down version of MacOS X used in the iPhone makes it more secure than computers running the full-blown operating system, Miller said.

For starters, the stripped-down version of the OS presents fewer options for attackers, removing applications and features such as support for Adobe Flash and Java, which they might otherwise be able to exploit for vulnerabilities. In addition, the iPhone includes hardware protection for data stored in memory and the phone is designed to only run software code that has been digitally signed by Apple.

The iPhone also requires applications to run in a sandbox, a security feature that isolates them from other applications and limits their access to the phone's capabilities. But SMS offers a way for attackers to get greater access to the phone's capabilities, Miller said.

"SMS is a great vector to attack the iPhone," he said.

Most often used to send brief text messages between cell phones, SMS can also send binary code to an iPhone, which then processes the code without any user interaction. Each SMS message is limited to 140 bytes, but longer sequences can be sent to the phone as multiple messages that are automatically reassembled.

This feature allows larger programs to be delivered to a phone, Miller said.

In addition, vulnerabilities found in the iPhone's SMS function give an attacker root access to the handset, Miller said. That's not the case for the iPhone's other applications, such as its browser, where vulnerabilities only give an attacker access to the application's sandbox.

"The iPhone is more secure than OS X, but SMS could be a critical vulnerability," Miller said.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags exploits and vulnerabilitiesApplesmsiPhoneMac OS XiPhone OS 3.0

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Sumner Lemon

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?