The re-factoring of XML validation for Tomcat 7.0.x re-introduced the vulnerability previously reported as CVE-2009-0783. This was initially reported as a memory leak. If a web application is the first web application loaded, this bug allows that web application to potentially view and/or alter the web.xml, context.xml and tld files of other web applications deployed on the Tomcat instance.
Source: Apache Tomcat 7.0.0 Through 7.0.16 Information Disclosure
