CVE-2021-22144 : Exploit Details and Defense Strategies

An uncontrolled recursion vulnerability has been identified in the Elasticsearch Grok parser in versions before 7.13.3 and 6.8.17. This vulnerability could be exploited by a user to execute a denial of service attack by crafting a malicious Grok query.

Understanding CVE-2021-22144

This CVE pertains to a specific vulnerability in Elasticsearch versions prior to 7.13.3 and 6.8.17 that could result in a denial of service (DoS) attack.

What is CVE-2021-22144?

The vulnerability in the Elasticsearch Grok parser allows an attacker to crash an Elasticsearch node by submitting a specially crafted Grok query. This could disrupt the availability of Elasticsearch services.

The Impact of CVE-2021-22144

If exploited, this vulnerability could lead to a denial of service attack, causing Elasticsearch nodes to crash and potentially impacting the availability of Elasticsearch services for users.

Technical Details of CVE-2021-22144

This section outlines the specific technical details related to the CVE.

Vulnerability Description

The vulnerability involves uncontrolled recursion in the Elasticsearch Grok parser, enabling an attacker to create a malicious query that triggers a DoS condition.

Affected Systems and Versions

Elasticsearch versions preceding 7.13.3 and 6.8.17 are impacted by this vulnerability. Users running these versions are advised to take immediate action.

Exploitation Mechanism

By submitting a specially crafted Grok query to Elasticsearch, an attacker can trigger the vulnerability and crash the Elasticsearch node, leading to a DoS scenario.

Mitigation and Prevention

Taking proactive steps to mitigate and prevent exploitation of CVE-2021-22144 is crucial for maintaining the security of Elasticsearch environments.

Immediate Steps to Take

Users should update their Elasticsearch installations to versions 7.13.3 or 6.8.17 to address the vulnerability and prevent potential exploitation.

Long-Term Security Practices

Implementing security best practices, such as regular updates and monitoring for security advisories, can help safeguard Elasticsearch deployments against known vulnerabilities.

Patching and Updates

It is recommended to regularly check for updates and security patches released by Elasticsearch to address vulnerabilities and enhance the overall security posture of Elasticsearch deployments.