1. Ubuntu Security Notices
  2. USN-4596-1

USN-4596-1: Tomcat vulnerabilities

Publication date

21 October 2020

Overview

Several security issues were fixed in Tomcat.

Releases

Packages

  • tomcat9 - Apache Tomcat 9 - Servlet and JSP engine

Details

It was discovered that Tomcat did not properly manage HTTP/2 streams. An
attacker could possibly use this to cause Tomcat to consume resources,
resulting in a denial of service. (CVE-2020-11996)

It was discovered that Tomcat did not properly release the HTTP/1.1
processor after the upgrade to HTTP/2. An attacker could possibly use this
to generate an OutOfMemoryException, resulting in a denial of service.
(CVE-2020-13934)

It was discovered that Tomcat did not properly validate the payload length
in a WebSocket frame. An attacker could possibly use this to trigger an
infinite loop, resulting in a denial of service. (CVE-2020-13935)

It was discovered that Tomcat did not properly deserialize untrusted data.
An attacker could possibly use this issue to execute arbitrary code.
(

It was discovered that Tomcat did not properly manage HTTP/2 streams. An
attacker could possibly use this to cause Tomcat to consume resources,
resulting in a denial of service. (CVE-2020-11996)

It was discovered that Tomcat did not properly release the HTTP/1.1
processor after the upgrade to HTTP/2. An attacker could possibly use this
to generate an OutOfMemoryException, resulting in a denial of service.
(CVE-2020-13934)

It was discovered that Tomcat did not properly validate the payload length
in a WebSocket frame. An attacker could possibly use this to trigger an
infinite loop, resulting in a denial of service. (CVE-2020-13935)

It was discovered that Tomcat did not properly deserialize untrusted data.
An attacker could possibly use this issue to execute arbitrary code.
(CVE-2020-9484)

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
20.04 focal libtomcat9-embed-java –  9.0.31-1ubuntu0.1
libtomcat9-java –  9.0.31-1ubuntu0.1
tomcat9 –  9.0.31-1ubuntu0.1
tomcat9-common –  9.0.31-1ubuntu0.1

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References

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