CVE-2020-26160 : What You Need to Know

JWT-Go before 4.0.0-preview1 allows attackers to bypass access restrictions, posing a security risk when presented to services lacking audience checks.

Understanding CVE-2020-26160

This CVE involves a vulnerability in JWT-Go that enables attackers to circumvent access restrictions, potentially leading to unauthorized access.

What is CVE-2020-26160?

JWT-Go before version 4.0.0-preview1 allows attackers to bypass intended access restrictions by exploiting a specific scenario related to the 'aud' claim in JWT tokens.

The Impact of CVE-2020-26160

CVSS Base Score: 7.5 (High)
Attack Vector: Network
Confidentiality Impact: High
Integrity Impact: None
This vulnerability can result in unauthorized access to services that do not perform their own audience checks.

Technical Details of CVE-2020-26160

This section provides detailed technical information about the CVE.

Vulnerability Description

The issue arises when JWT-Go encounters []string{} for m["aud"], causing a type assertion failure and setting the value of 'aud' to "", potentially leading to unauthorized access.

Affected Systems and Versions

Affected Version: JWT-Go before 4.0.0-preview1

Exploitation Mechanism

Attack Complexity: Low
Privileges Required: None
Scope: Unchanged
User Interaction: None
The vulnerability can be exploited over a network without requiring user interaction.

Mitigation and Prevention

To address CVE-2020-26160, follow these mitigation strategies:

Immediate Steps to Take

Upgrade to JWT-Go version 4.0.0-preview1 or later.
Implement additional audience checks in services that process JWT tokens.

Long-Term Security Practices

Regularly update and patch JWT-Go and related dependencies.
Conduct security audits to identify and address vulnerabilities proactively.

Patching and Updates

Stay informed about security updates for JWT-Go and promptly apply patches to mitigate known vulnerabilities.