Microsoft Internet Explorer 4.0 through 6.0 could allow local users to differentiate between alphanumeric and non-alphanumeric characters used in a password by pressing certain control keys that jump between non-alphanumeric characters, which makes it easier to conduct a brute-force password guessing attack.

Internet Explorer before 5.5 forwards cached user credentials for a secure web site to insecure pages on the same web site, which could allow remote attackers to obtain the credentials by monitoring connections to the web server, aka the "Cached Web Credentials" vulnerability.

Internet Explorer 5.x does not warn a user before opening a Microsoft Access database file that is referenced within ActiveX OBJECT tags in an HTML document, which could allow remote attackers to execute arbitrary commands, aka the "IE Script" vulnerability.

Internet Explorer 4.x and 5.x does not properly re-validate an SSL certificate if the user establishes a new SSL session with the same server during the same Internet Explorer session, aka one of two different "SSL Certificate Validation" vulnerabilities.

Internet Explorer 4.x and 5.x does not properly verify all contents of an SSL certificate if a connection is made to the server via an image or a frame, aka one of two different "SSL Certificate Validation" vulnerabilities.

Internet Explorer 4.x and 5.x allows remote attackers to execute arbitrary commands via a buffer overflow in the ActiveX parameter parsing capability, aka the "Malformed Component Attribute" vulnerability.

Internet Explorer 4.0 and 5.0 allows a malicious web site to obtain client cookies from another domain by including that domain name and escaped characters in a URL, aka the "Unauthorized Cookie Access" 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 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.