Severity: Important Vendor: The Apache Software Foundation Versions Affected: Apache Tomcat 9.0.0.M1 to 9.0.0.M20 Apache Tomcat 8.5.0 to 8.5.14 Apache Tomcat 8.0.0.RC1 to 8.0.43 Apache Tomcat 7.0.0 to 7.0.77 Earlier, unsupported versions have not been analysed but are likely to be affected Description: The error page mechanism of the Java Servlet Specification requires that, when an error occurs and an error page is configured for the error that occurred, the original request and response are forwarded to the error page. This means that the request is presented to the error page with the original HTTP method. If the error page is a static file, expected behaviour is to serve content of the file as if processing a GET request, regardless of the actual HTTP method. Tomcat's Default Servlet did not do this. Depending on the original request this could lead to unexpected and undesirable results for static error pages including, if the DefaultServlet is configured to permit writes, the replacement or removal of the custom error page. Notes for other user provided error pages: - Unless explicitly coded otherwise, JSPs ignore the the HTTP method. JSPs used as error pages must must ensure that they handle any error dispatch as a GET request, regardless of the actual method. - By default, the response generated by a Servlet does depend on the HTTP method. Custom Servlets used as error pages must ensure that they handle any error dispatch as a GET request, regardless of the actual method. Mitigation: Users of the affected versions should apply one of the following mitigations: - Upgrade to Apache Tomcat 9.0.0.M21 or later - Upgrade to Apache Tomcat 8.5.15 or later - Upgrade to Apache Tomcat 8.0.44 or later - Upgrade to Apache Tomcat 7.0.78 or later Credit: This issue was reported responsibly to the Apache Tomcat Security Team by Aniket Nandkishor Kulkarni from Tata Consultancy Services Ltd, Mumbai, India as a vulnerability that allowed the restrictions on OPTIONS and TRACE requests to be bypassed. The full implications of this issue were then identified by the Tomcat Security Team. History: 2017-06-06 Original advisory References: [1] http://tomcat.apache.org/security-9.html [2] http://tomcat.apache.org/security-8.html [3] http://tomcat.apache.org/security-7.html