[SECURITY] CVE-2021-42340 Apache Tomcat DoS

[Mark Thomas <ma...@apache.org>]

CVE-2021-42340 Denial of Service

Severity: Important

Vendor: The Apache Software Foundation

Versions Affected:
Apache Tomcat 10.1.0-M1 to 10.1.0-M5
Apache Tomcat 10.0.0-M10 to 10.0.11
Apache Tomcat 9.0.40 to 9.0.53
Apache Tomcat 8.5.60 to 8.5.71

Description:
The fix for bug 63362 introduced a memory leak. The object introduced to 
collect metrics for HTTP upgrade connections was not released for 
WebSocket connections once the WebSocket connection was closed. This 
created a memory leak that, over time, could lead to a denial of service 
via an OutOfMemoryError.

Mitigation:
Users of the affected versions should apply one of the following
mitigations:
- Upgrade to Apache Tomcat 10.1.0-M6 or later
- Upgrade to Apache Tomcat 10.0.12 or later
- Upgrade to Apache Tomcat 9.0.54 or later
- Upgrade to Apache Tomcat 8.5.72 or later

History:
2021-10-14 Original advisory
2021-10-14 Correct CVE reference in body of advisory

References:
[1] https://tomcat.apache.org/security-10.html
[2] https://tomcat.apache.org/security-9.html
[3] https://tomcat.apache.org/security-8.html