Undertow Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling) Vulnerability - CVE-2017-7559

In Undertow 2.x before 2.0.0.Alpha2 1.4.x before 1.4.17.Final and 1.3.x before 1.3.31.Final it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited in conjunction with a proxy that also permitted the invalid characters but with a different interpretation to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache perform an XSS attack or obtain sensitive information from requests other than their own.