Microsoft announced to be aware of a new IE zero-day vulnerability (CVE-2013-3893) that affects Windows browsers IE 8 and IE 9 recently targeted by hackers. Microsoft confirmed that the flaw was unknown before the attacks and for this reason it is working on an official patch to protect its customers browser. The vulnerability exists in the way that Internet Explorer accesses an object in memory that has been deleted or has not been properly allocated. The vulnerability may corrupt memory in a way that could allow an attacker to execute arbitrary code in the context of the current user.”]
Source: http://securityaffairs.co/wordpress/17858/hacking/new-microsoft-ie-zero-day.html