iDefense Security Advisory 07.20.11 - Remote exploitation of a memory corruption vulnerability in Apple Inc.'s Safari browser could allow an attacker to execute arbitrary code with the privileges of the current user. Safari is Apple's Web browser and is based on the open source WebKit browser engine. This vulnerability occurs when Safari incorrectly handles an error state when encountering a broken XHTML tag. Specifically, the tag enclosing the tag being processed is freed and is then referenced after it has already been freed. This can lead to the execution of arbitrary code. Safari versions prior to 5.1 and 5.0.6 are vulnerable.
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