CVE-2020-11996 Apache Tomcat HTTP/2 Denial of Service Severity: Important Vendor: The Apache Software Foundation Versions Affected: Apache Tomcat 10.0.0-M1 to 10.0.0-M5 Apache Tomcat 9.0.0.M1 to 9.0.35 Apache Tomcat 8.5.0 to 8.5.55 Description: A specially crafted sequence of HTTP/2 requests could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive. Mitigation: - Upgrade to Apache Tomcat 10.0.0-M6 or later - Upgrade to Apache Tomcat 9.0.36 or later - Upgrade to Apache Tomcat 8.5.56 or later Credit: This issue was reported publicly via the Apache Tomcat Users mailing list without reference to the potential for DoS. The DoS risks were identified by the Apache Tomcat Security Team. References: [1]

http://tomcat.apache.org/security-10.html

[2]

http://tomcat.apache.org/security-9.html

[3]

http://tomcat.apache.org/security-8.html