Cross-site scripting (XSS) vulnerability in the Reverse Proxy Plug-in in Sun Java System Web Server 6.1 before SP11 allows remote attackers to inject arbitrary web script or HTML via the query string in situations that result in a 502 Gateway error.

Sun SunONE web server 6.1 SP1 allows remote attackers to poison the web cache, bypass web application firewall protection, and conduct XSS attacks via an HTTP request with both a "Transfer-Encoding: chunked" header and a Content-Length header, which causes SunONE to incorrectly handle and forward the body of the request in a way that causes the receiving server to process it as a separate HTTP request, aka "HTTP Request Smuggling."