September 10, 2009, 4:40 PM — Apple yesterday issued a pair of updates that patched 10 vulnerabilities in its iPhone software and four in its QuickTime player program.
One of the 10 flaws in the iPhone's software was related to a bug that Apple patched in a hurry last July, just a day after security researchers showed how hackers could hijack iPhones with a series of malicious text messages.
Wednesday's update patched a vulnerability in the iPhone's telephony service that attackers could exploit to disrupt SMS (Short Message Service) text messaging on the smartphone, Apple said in an accompanying security advisory . Apple credited Charlie Miller of Independent Security Evaluators and Collin Mulliner from the Technical University Berlin with reporting the flaw.
In late July, Miller and Mulliner demonstrated a more serious SMS vulnerability at the Black Hat security conference, showing how hackers could send apparently-harmless text messages, including messages that the iPhone's owner never sees, to silently operate smartphone features such as its camera or microphone.
Apple quashed that bug in a single-patch update released July 31.
"This was a different bug [than July's]," said Miller in an e-mail exchange. "We revealed it at Black Hat but hadn't given Apple advance notice since it was pretty minor. It was only a DoS [denial of service] and didn't even interrupt calls."
At the Black Hat presentation Miller and Mulliner gave in July, Miller said he thought there were more SMS bugs to be found in the iPhone; the pair had been able to test only a small subset of the possible scenarios.
Only two of the 10 vulnerabilities Apple patched with iPhone 3.1 were classified as critical. Although Apple doesn't rank or score flaws like other vendors, it uses the phrasing "arbitrary code execution" to denote vulnerabilities that could be used by attackers to gain complete control of the iPhone.
Of the two critical flaws, the first could be triggered by rigged audio files, while the second could be exploited through a malicious Web site designed to leverage a bug in WebKit, the rendering engine that powers the iPhone's Safari browser. Four of the 10 vulnerabilities involved WebKit.
Other vulnerabilities had the potential to expose an iPhone owner's Microsoft Exchange e-mail account, let unauthorized people access deleted e-mails or a supposedly-locked iPhone, or disclose sensitive information on the smartphone.