CVE-2021-20326 Explained : Impact and Mitigation

A denial of service vulnerability has been identified in MongoDB Server versions prior to 4.4.4. A specially crafted query by an authorized user could trigger this issue, leading to a significant impact on availability. Here's what you need to know about CVE-2021-20326.

Understanding CVE-2021-20326

This section will provide insights into the nature and impact of the vulnerability.

What is CVE-2021-20326?

The vulnerability in question allows a user with specific find query privileges to execute a specially crafted query that results in a denial of service within MongoDB Server versions prior to 4.4.4.

The Impact of CVE-2021-20326

The impact of this vulnerability is rated as MEDIUM severity based on the CVSS v3.1 base score of 6.5. It has a HIGH availability impact, as an attacker can disrupt the service by triggering the denial of service vulnerability.

Technical Details of CVE-2021-20326

Let's delve into the technical aspects of CVE-2021-20326 to understand how it affects systems and what can be done to mitigate the risk.

Vulnerability Description

The vulnerability arises due to improper input validation, specifically in the handling of find queries within MongoDB Server versions prior to 4.4.4.

Affected Systems and Versions

MongoDB Inc.'s MongoDB Server versions less than 4.4.4 are affected by CVE-2021-20326. Users of these versions are urged to take immediate action to secure their systems.

Exploitation Mechanism

The vulnerability can be exploited remotely with low privileges required. An attacker needs to send a specially crafted query over the network to trigger the denial of service condition.

Mitigation and Prevention

In this section, we will discuss the necessary steps to mitigate the risk posed by CVE-2021-20326 and prevent potential attacks.

Immediate Steps to Take

It is recommended to update MongoDB Server to version 4.4.4 or higher to address the vulnerability and prevent exploitation. Additionally, restrict network access to MongoDB instances to trusted entities.

Long-Term Security Practices

Implement a solid input validation mechanism in your applications and regularly update and patch MongoDB Server to stay protected against known vulnerabilities.

Patching and Updates

Stay informed about security advisories from MongoDB Inc. and promptly apply patches and updates to ensure the ongoing security of your MongoDB Server installation.