source: https://www.securityfocus.com/bid/27128/info
ExpressionEngine is prone to an HTTP-response-splitting vulnerability and a cross-site scripting vulnerability because it fails to properly sanitize user-supplied input.
An attacker may leverage these issues to execute arbitrary script code in the browser of an unsuspecting user, steal cookie-based authentication credentials, and influence how web content is served, cached, or interpreted. This could aid in various attacks that try to entice client users into a false sense of trust.
ExpressionEngine 1.2.1 is vulnerable to these issues; other versions may also be affected.
http://www.example.com/index.php?URL=%0AContent-Type:html%0A%0A%3Cscript%3Ealert(document.cookie)%3C/script%3E
