Arch Linux Security Advisory ASA-202006-16
=========================================
Severity: Medium
Date    : 2020-06-28
CVE-ID  : CVE-2020-11996
Package : tomcat8
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1197

Summary
======
The package tomcat8 before version 8.5.56-1 is vulnerable to denial of
service.

Resolution
=========
Upgrade to 8.5.56-1.

# pacman -Syu "tomcat8>=8.5.56-1"

The problem has been fixed upstream in version 8.5.56.

Workaround
=========
None.

Description
==========
A denial of service has been found in Apache Tomcat before 9.0.36 and
8.5.56, where 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.

Impact
=====
A remote attacker might be able to cause a denial of service via a
specially crafted sequence of HTTP/2 requests.

References
=========
https://www.openwall.com/lists/oss-security/2020/06/25/6
https://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.36
https://github.com/apache/tomcat/commit/9a0231683a77e2957cea0fdee88b193b30b0c976
https://tomcat.apache.org/security-8.html#Fixed_in_Apache_Tomcat_8.5.56
https://github.com/apache/tomcat/commit/c8acd2ab7371e39aeca7c306f3b5380f00afe552
https://security.archlinux.org/CVE-2020-11996