Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The XSS Filter in Microsoft Internet Explorer 8.0 Beta 2 disables itself upon encountering a certain X-XSS-Protection HTTP header, which allows remote attackers to bypass the XSS protection mechanism and conduct XSS attacks by injecting this header after a CRLF sequence. NOTE: the vendor has reportedly stated that the XSS Filter intentionally does not attempt to "address every conceivable XSS attack scenario."
CWE-79 - Cross Site Scripting
Cross-Site Scripting, commonly referred to as XSS, is the most dominant class of vulnerabilities. It allows an attacker to inject malicious code into a pregnable web application and victimize its users. The exploitation of such a weakness can cause severe issues such as account takeover, and sensitive data exfiltration. Because of the prevalence of XSS vulnerabilities and their high rate of exploitation, it has remained in the OWASP top 10 vulnerabilities for years.