iPhone OS 3.1.3 corrects flaws in several components of the operating system, including CoreAudio, ImageIO, Recovery Mode, and WebKit.
If exploited, some of the security flaws could enable a hacker to run code on a person's iPhone or iPod Touch and access data on the devices, Apple said Tuesday. File formats that could be used to exploit some of the flaws include MP4 audio files and TIFF image files.
Apple computers were once ignored by hackers who preferred to go after the more ubiquitous Windows PCs. However, the growing popularity of Apple Macs, iPods, and iPhones is attracting the attention of cybercriminals.
At last summer's Black Hat technical security conference, experts demonstrated security flaws they found in Apple products. The company has a policy of not commenting on alleged security problems, but only discusses flaws after it releases fixes.
One attention-getter at Black Hat was security researcher Dai Zovi, who predicted that hackers would start targeting Macs as their market share grow. He also predicted Macs would prove more vulnerable than expected.
"There's not magic fairy dust protecting Macs," Zovi told Reuters news agency.
At the same conference, Charlie Miller, author of The Mac Hacker's Handbook, said Apple's security efforts are increasing, but not fast enough to protect against hackers as the company's market share grows.