Phreakers could seize control of users' mobile handsets, send arbitrary messages or render phones unusable because of a brace of Java-related security vulnerabilities, a security researcher warns. The problems have been demonstrated on a Nokia 6310i handset and might also apply to other phones running flawed implementations of mobile Java (J2ME).
Each of the vulnerabilities can be used to "completely break Java security on a mobile device and to obtain access to the phone data and underlying operating system's functionality", according to Adam Gowdiak, a security researcher at Poland's Poznan Supercomputing and Networking Center, who discovered the problems. Both vulnerabilities are implementation flaws in Java Virtual Machine developed by Sun Microsystems.
Gowdiak has demonstrated how malicious Java applications can do all manner of mischief on a Nokia 6310i phone. Exploits include: the ability to access and steal data from the phone (phonebook information, SMS messages, information about dialled numbers, etc.), sending arbitrary SMS messages to arbitrary phone numbers and transferring data to and form the net without a user's knowledge. Writing to the permanent memory of the a Nokia 6310i phone - creating a "backdoor" on a phone or making it unusable - have also been demonstrated by Gowdiak. The flaws are far from easy to exploit but their severity gives serious cause for concern.
Mikko Hyppönen, director of anti-virus research at Finnish AV firm F-Secure, commended the quality of Gowdiak's research. "I'm really surprised these holes haven't made more noise, as everything seems to check out and these are really widespread problems, affecting almost a hundred different phone models out there.
Although he hasn't tested it, Gowdiak's reckons the vulnerabilities he has demonstrated on Nokia 6310i phones might also apply to mobiles from Nokia, Siemens, Panasonic, Samsung, Motorola and others underpinned by Java technology. Gowdiak outlined his findings at the Hack in the Box Security Conference earlier this month in Kuala Lumpur, Malaysia. "According to my knowledge, this is the first time, so serious flaws affecting mobile Java (J2ME) have been published," he told El Reg.
Gowdiak has produced a paper on is research available here (PDF). ®