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Not the most riveting of updates, but I am sure it serves an important security purpose.

Installed in a matter of seconds on my Mac and PC.
 
What they fixed

Visiting a malicious website may lead to arbitrary code execution

An implementation issue exists in QuickTime for Java, which may allow instantiation or manipulation of objects outside the bounds of 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. This update addresses the issue by performing additional validation of Java applets.

Visiting a malicious website may lead to the disclosure of sensitive information

A design issue exists in QuickTime for Java, which may allow a web browser's memory to be read by a Java applet. 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 the disclosure of sensitive information. This update addresses the issue by clearing memory before allowing it to be used by untrusted Java applets.
 
It made me restart and iTunes started up kinda slow. It seems to be alright now though. 10.3.9 eMac 1gHz
 
Could it be that the 10.4 people do not need a restart whereas 10.3.9 do? My Tiger G5 iMac did not need a restart whereas my Panther PB did.
 
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