Apple updated QuickTime to version 7.3 recently to address a much-exploited bug, but a new QuickTime vulnerability has emerged, prompting security agencies to issue warnings to those running QuickTime on either Windows XP or Windows Vista. There is no word yet on whether Mac OS X is vulnerable to the new QuickTime bug. Apple's QuickTime is vulnerable to malware disguised as streaming video, and attack code has been published on the milw0rm.com web site. According to the U.S. Computer Emergency Readiness Team, QuickTime versions 7.2 and 7.3, and perhaps earlier versions, contain a buffer-overflow bug. "Apple QuickTime contains a stack buffer overflow vulnerability in the way QuickTime handles the RTSP Content-Type header," US-CERT said. "This vulnerability may be exploited by convincing a user to connect to a specially crafted RTSP stream." RTSP is the Real-Time Streaming Protocol, which QuickTime supports. When users click on a link for a malicious RTSP stream, an attacker might be able to execute arbitrary code on the compromised system. Solutions of limiting this vulnerability until a new patch is released, can be found here.