Microsoft Internet Explorer 6 drops DNS pins based on failed connections to irrelevant TCP ports, which makes it easier for remote attackers to conduct DNS rebinding attacks, as demonstrated by a port 81 URL in an IMG SRC, when the DNS pin had been established for a session on port 80, a different issue than CVE-2006-4560.

Internet Explorer 6 on Windows XP SP2 allows remote attackers to execute arbitrary JavaScript in the context of the browser's session with an arbitrary intranet web server, by hosting script on an Internet web server that can be made inaccessible by the attacker and that has a domain name under the attacker's control, which can force the browser to drop DNS pinning and perform a new DNS query for the domain name after the script is already running.