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AUSCERT External Security Bulletin Redistribution
ESB-2020.2203
CVE-2020-11996 Apache Tomcat HTTP/2 Denial of Service
26 June 2020
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AusCERT Security Bulletin Summary
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Product: Apache Tomcat
Operating System: UNIX variants (UNIX, Linux, OSX)
Windows
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-11996
Original Bulletin:
https://www.mail-archive.com/announce@apache.org/msg05953.html
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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
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The University of Queensland
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