The Microsoft virtual machine (VM) in Internet Explorer 4.x and 5.x allows a remote attacker to read files via a malicious Java applet that escapes the Java sandbox, aka the "VM File Reading" vulnerability.

Internet Explorer 4.x and 5.x allows remote web servers to access files on the client that are outside of its security domain, aka the "Image Source Redirect" vulnerability.

Internet Explorer 5 does not modify the security zone for a document that is being loaded into a window until after the document has been loaded, which could allow remote attackers to execute Javascript in a different security context while the document is loading.

Buffer overflow in Internet Explorer 4.0 via EMBED tag.

Internet Explorer 4.0 allows remote attackers to read arbitrary text and HTML files on the user's machine via a small IFRAME that uses Dynamic HTML (DHTML) to send the data to the attacker, aka the Freiburg text-viewing issue.

When a Web site redirects the browser to another site, Internet Explorer 3.02 and 4.0 automatically resends authentication information to the second site, aka the "Page Redirect Issue."

Buffer overflow in the Window.External function in the JScript Scripting Engine in Internet Explorer 4.01 SP1 and earlier allows remote attackers to execute arbitrary commands via a malicious web page.

Internet Explorer 4 treats a 32-bit number ("dotless IP address") in the a URL as the hostname instead of an IP address, which causes IE to apply Local Intranet Zone settings to the resulting web page, allowing remote malicious web servers to conduct unauthorized activities by using URLs that contain the dotless IP address for their server.

Internet Explorer 5.0 and 5.01 allows remote attackers to bypass the cross frame security policy and read files via the external.NavigateAndFind function.

Internet Explorer 5.01 and earlier allows a remote attacker to create a reference to a client window and use a server-side redirect to access local files via that window, aka "Server-side Page Reference Redirect."