OWASP ESAPI Cross-Site Scripting Vulnerability

OWASP ESAPI is a free, open source, web application security control library that makes it easier for programmers to write lower-risk applications. cross-site scripting vulnerabilities exist in versions of OWASP ESAPI prior to 2.3.0.0, which originate from the " onsiteURL" regular expression error in the antisamy-esapi.xml configuration file, which can be exploited by attackers to execute JavaScript code on the client side.