Apple has released an update that patches more than a dozen OS X vulnerabilities, several of which can lead to the remote execution of malicious code.
The most serious vulnerability resides in an OS X feature called mDNSResponder, which enables computers to locate and connect to devices such as printers and webcams on a local network. An attacker could use it to execute code by sending malicious packets to Macs connected to the same subnet, making the exploit ideal for use in internet cafes and offices.
Code exploiting the vulnerability has already been circulated by Immunity, a company that provides intelligence to security providers, according to Immunity's CTO, Dave Aitel.
"Remote roots like this don't come out every day," he said of the vulnerability.
Apple credited Michael Lynn of Juniper Networks for reporting the vulnerability. Lynn was the Cisco security researcher whose bosses threatened him with legal action in 2005 after publicly discussing vulnerability details in Cisco routers.
Yesterday's update was the fifth time in as many months that Apple has released to patch multiple security holes in its software. Apple has released other security patches this year, most recently to fix a high-profile vulnerability in QuickTime that allowed a hacker in a contest to publicly hijack a brand new MacBook Pro.
Among the other serious holes plugged in yesterday's update is flaw in OS X's CoreGraphics. That vulnerability could allow attackers to run code on a victim's machine by enticing users to open a maliciously crafted PDF file. ®