CVE-2021-21378 : Security Advisory and Response

A detailed analysis of CVE-2021-21378 focusing on the impact, technical details, and mitigation strategies.

Understanding CVE-2021-21378

This section delves into the specifics of the vulnerability associated with JWT authentication bypass in Envoy version 1.17.0.

What is CVE-2021-21378?

The CVE-2021-21378 vulnerability in Envoy enables attackers to circumvent authentication by leveraging a JWT token with an unrecognized issuer.

The Impact of CVE-2021-21378

The vulnerability poses a high risk with a CVSS base score of 8.2, primarily impacting the confidentiality of the system.

Technical Details of CVE-2021-21378

This section provides an in-depth look into the technical aspects of the CVE, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

In Envoy version 1.17.0, the JWT Authentication filter mishandles JWT tokens with unknown issuers, allowing unauthorized access.

Affected Systems and Versions

Envoy version 1.17.0 is confirmed to be affected by this vulnerability, leaving systems exposed to potential exploits.

Exploitation Mechanism

Attackers exploit this vulnerability by presenting JWT tokens with unrecognized issuers, bypassing authentication measures in the system.

Mitigation and Prevention

This section outlines the steps to mitigate the risks associated with CVE-2021-21378, ensuring system security and integrity.

Immediate Steps to Take

Users are advised to update Envoy to version 1.17.1, where the vulnerability has been patched to prevent authentication bypass.

Long-Term Security Practices

Implementing robust authentication protocols and regularly updating security measures can enhance long-term protection against similar vulnerabilities.

Patching and Updates

Frequent patch management and system updates are crucial in maintaining a secure environment and preventing potential exploits.