Apple issued a pair of updates yesterday 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.
Apple has had problems with the iPhone's password-locking feature before. In August 2008, a researcher discovered a bug that allowed users to bypass a password-protected lock had resurfaced in iPhone 2.0. Apple quickly confirmed the bug, and patched it a month later.
Users can wait out the update interval -- iTunes automatically checks Apple's update servers once a week -- or retrieve iPhone 3.1 manually by selecting "Check for Update" under the iTunes Help menu and then docking the iPhone to a PC or Macintosh.
Apple also updated QuickTime for both the Mac and Windows to version 7.6.4, fixing four flaws, all critical.
According to Apple's advisory, all four vulnerabilities involved QuickTime's handling of file formats, a common cause of the player's problems. Two of the vulnerabilities related to improper parsing of H.264 movie files, while the remaining pair were due to issues in handling MPEG-4 video files and FlashPix image files.
"These are the kinds of bugs one would come to expect from QuickTime," said Andrew Storms, director of security operations at nCircle Network Security, echoing comments regularly made by experts about QuickTime's knack for harboring file format flaws.
Two of the four vulnerabilities were reported to Apple by 3Com TippingPoint's bug bounty program, Zero Day Initiative (ZDI). Three months ago, when Apple last patched QuickTime, six of the 10 flaws had been reported by the ZDI program.
Monday's update was Apple's third this year for the player, which has been patched against 21 vulnerabilities so far in 2009; last year, Apple patched 30 QuickTime bugs.
Updating to QuickTime 7.6.4, however, will disable the QuickTime Pro functionality of versions earlier than v. 7, Apple acknowledged in a separate support document. QuickTime 6 Pro users, for example, will need to buy the $29.99 QuickTime 7 Pro activation code to restore the lost features if they upgrade to 7.6.4.
Mac users can upgrade to QuickTime 7.6.4 using the operating system's built-in Software Update feature, while Windows users can either download the new QuickTime from Apple's site or use the optional Windows update tool.