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                             CERT-Renater

                 Note d'Information No. 2020/VULN367
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DATE                : 26/06/2020

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Apache Tomcat versions prior to
                               10.0.0-M6, 9.0.35, 8.5.55.

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http://mail-archives.apache.org/mod_mbox/tomcat-announce/202006.mbox/%3cfd56bc1d-1219-605b-99c7-946bf7bd8ad4@apache.org%3e
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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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+ CERT-RENATER        | tel : 01-53-94-20-44            +
+ 23/25 Rue Daviel    | fax : 01-53-94-20-41            +
+ 75013 Paris         | email:cert@support.renater.fr   +
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