This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Internet Explorer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the way Internet Explorer handles HTTP 302 redirects to CDL protocols. When Internet Explorer tries to determine who is responsible for handling the protocol redirect it fails to keep a correct reference counter to a Transaction object which results in a use-after-free vulnerability. This can be leveraged into remote code execution under the context of the current user.