Improper Input Validation
Microsoft Internet Explorer 5.01 through 6 allows remote attackers to conduct phishing attacks by spoofing the address bar and other parts of the trust UI via unknown methods that allow "window content to persist" after the user has navigated to another site, aka the "Address Bar Spoofing Vulnerability." NOTE: this is a different vulnerability than CVE-2006-1626.
CWE-20 - Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.