CVE-2021-3629 : Exploit Details and Defense Strategies

Undertow prior to versions 2.0.40.Final and 2.2.11.Final is impacted by a security vulnerability related to flow control handling over HTTP/2. This flaw could lead to a denial of service affecting the server's availability.

Understanding CVE-2021-3629

This CVE involves a potential security issue in Undertow that could result in a denial of service attack on the server due to improper flow control handling over HTTP/2.

What is CVE-2021-3629?

CVE-2021-3629 is a vulnerability found in Undertow versions prior to 2.0.40.Final and 2.2.11.Final. It is related to flow control handling over HTTP/2, posing a risk to the server's availability.

The Impact of CVE-2021-3629

The primary impact of this vulnerability is on the availability of the affected server. If exploited, it could lead to overhead or denial of service, affecting the normal functioning of the server.

Technical Details of CVE-2021-3629

This section will delve into the specific technical aspects of CVE-2021-3629, including vulnerability description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

The flaw in Undertow allows attackers to exploit flow control handling over HTTP/2, potentially causing a denial of service attack on the server by creating overhead.

Affected Systems and Versions

Undertow versions prior to 2.0.40.Final and 2.2.11.Final are vulnerable to CVE-2021-3629 due to improper flow control handling over HTTP/2.

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating flow control mechanisms over HTTP/2 to overwhelm the server, resulting in service disruption.

Mitigation and Prevention

In this section, we will discuss the necessary steps to mitigate the risks associated with CVE-2021-3629 and prevent potential exploitation.

Immediate Steps to Take

To address this vulnerability, it is crucial to update Undertow to versions 2.0.40.Final or 2.2.11.Final to eliminate the security risk posed by improper flow control handling over HTTP/2.

Long-Term Security Practices

Implementing robust security measures and staying informed about potential vulnerabilities in Undertow can help enhance the overall security posture of the server infrastructure.

Patching and Updates

Regularly applying security patches released by Undertow and staying updated on the latest security advisories is essential to prevent exploitation of known vulnerabilities like CVE-2021-3629.