CVE-2021-41803 : Security Advisory and Response

HashiCorp Consul 1.8.1 up to 1.11.8, 1.12.4, and 1.13.1 do not properly validate the node or segment names prior to interpolation and usage in JWT claim assertions with the auto config RPC.

Understanding CVE-2021-41803

This CVE involves HashiCorp Consul versions 1.8.1 up to 1.11.8, 1.12.4, and 1.13.1 which lack proper validation of node or segment names in JWT claim assertions.

What is CVE-2021-41803?

CVE-2021-41803 is a vulnerability where HashiCorp Consul versions do not adequately validate node or segment names before using them in JWT claim assertions.

The Impact of CVE-2021-41803

Attackers can exploit this vulnerability to manipulate JWT claims and potentially gain unauthorized access.

Technical Details of CVE-2021-41803

This section covers the technical aspects of the CVE.

Vulnerability Description

The issue lies in the lack of validation of node or segment names, leading to potential security risks in Consul's JWT claim assertions.

Affected Systems and Versions

Versions: HashiCorp Consul 1.8.1 up to 1.11.8, 1.12.4, and 1.13.1
Status: Affected

Exploitation Mechanism

Attackers can exploit the lack of validation to alter JWT claims and possibly bypass security mechanisms.

Mitigation and Prevention

Protect your systems from this vulnerability.

Immediate Steps to Take

Upgrade to HashiCorp Consul versions 1.11.9, 1.12.5, or 1.13.2 which include fixes.
Monitor and review JWT claims for any suspicious activity.

Long-Term Security Practices

Implement strict input validation in applications to prevent similar issues.
Regularly update and patch all software components in your environment.
Educate teams on secure coding practices.

Patching and Updates

Apply patches provided by HashiCorp promptly to address the vulnerability.