Apple has plugged two holes in its QuickTime media player that could create serious security problems for people tricked into visiting malicious websites. The release, which is available for both Windows and Mac platforms, is Apple's second security patch in less than a week.

The most serious of the two vulnerabilities involves QuickTime's implementation of Java, which could allow for the manipulation of objects outside what should be allowed by the allocated heap.

"By enticing a user to visit a web page containing a maliciously crafted Java applet, an attacker can trigger the issue which may lead to arbitrary code execution," Apple said in this advisory.

Apple gave credit to John McDonald, Paul Griswold, and Tom Cross of IBM Internet Security Systems X-Force and Dyon Balding of Secunia Research for reporting the flaw.

The other vulnerability also resides in the way QuickTime works with Java and could allow a maliciously crafted applet to read a web browser's memory. That could allow an attacker access to potentially sensitive information, Apple said.

If it seems like Apple security team has been working overtime, it's because it has. On Thursday, the maker of the increasingly popular iMac and iBook released its fifth mega patch in as many months. This fixed more than a dozen security vulnerabilities in OS X. Less than three weeks earlier, Apple patched another hole in QuickTime that could also allow a booby-trapped website to execute malicious code on unwitting Mac users.

QuickTime has emerged as one of the more vulnerable Apple packages, with at least four security updates this year. QuickTime's susceptibility is due in part to its ability to run on both Windows and OS X and its wide use (and occasional abuse) on sites such MySpace.

Apple's update is here. ®