When accessing a website that requires IE8 or later directly, the following user agent string is in the headers:
Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko
When the site is accessed through CAM, the following user agent string is detected instead, and the browser is redirected to a page that says the browser needs to be updated:
Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; InfoPath.3; .NET4.0C; .NET4.0E; .NET CLR 1.1.4322)
Users of Google Chrome are not affected by this problem, their user agent strings are unchanged.