Microsoft Internet Explorer 8 and 9, when the Proxy Settings configuration has the same Proxy address and Port values in the HTTP and Secure rows, does not properly reuse TCP sessions to the proxy server, which allows remote attackers to obtain sensitive information intended for a specific host via a crafted HTML document that triggers many HTTPS requests and then triggers an HTTP request to that host, as demonstrated by reading a Cookie header, aka MSRC 12096gd.