CVE-2020-13943 : Security Advisory and Response

Apache Tomcat versions 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37, and 8.5.0 to 8.5.57 are affected by a vulnerability that could lead to information disclosure.

Understanding CVE-2020-13943

This CVE involves a potential security issue in Apache Tomcat that could result in users seeing responses for unexpected resources.

What is CVE-2020-13943?

If an HTTP/2 client connecting to the affected Apache Tomcat versions exceeded the maximum number of concurrent streams, it could lead to the display of responses for unintended resources.

The Impact of CVE-2020-13943

The vulnerability could allow HTTP headers from a previous request to be included in a subsequent request, potentially exposing sensitive information to unauthorized users.

Technical Details of CVE-2020-13943

Apache Tomcat's vulnerability involves information disclosure due to improper handling of HTTP/2 connections.

Vulnerability Description

When the agreed maximum number of concurrent streams is exceeded, subsequent requests may contain headers from previous requests, leading to potential information exposure.

Affected Systems and Versions

Apache Tomcat 10.0.0-M1 to 10.0.0-M7
Apache Tomcat 9.0.0.M1 to 9.0.37
Apache Tomcat 8.5.0 to 8.5.57

Exploitation Mechanism

Attackers could exploit this vulnerability by sending malicious requests that exceed the agreed maximum number of concurrent streams, allowing them to view unintended resources.

Mitigation and Prevention

To address CVE-2020-13943, consider the following steps:

Immediate Steps to Take

Apply the necessary security updates provided by Apache Tomcat.
Monitor network traffic for any suspicious activity.
Implement strict HTTP/2 connection limits to prevent exploitation.

Long-Term Security Practices

Regularly update Apache Tomcat to the latest version to patch known vulnerabilities.
Educate users on safe browsing practices to minimize the risk of exploitation.

Patching and Updates

Stay informed about security advisories from Apache Tomcat and promptly apply patches to secure your systems.