CVE-2023-34236 Explained : Impact and Mitigation

A detailed article about an Information Disclosure Vulnerability in Weave GitOps Terraform Controller.

Understanding CVE-2023-34236

In this section, we will explore the impact, technical details, and mitigation steps for CVE-2023-34236.

What is CVE-2023-34236?

Weave GitOps Terraform Controller is a controller for Flux to reconcile Terraform resources in a GitOps way. A vulnerability has been identified in Weave GitOps Terraform Controller that allows an authenticated remote attacker to view sensitive information. The vulnerability arises from Weave GitOps Terraform Runners (

tf-runner

) where sensitive data is inadvertently printed in pod logs.

The Impact of CVE-2023-34236

The vulnerability in Weave GitOps Terraform Controller could lead to exposure of sensitive information to unauthorized actors. Attackers can exploit this to gain unauthorized access or control over resources managed by the Terraform controller.

Technical Details of CVE-2023-34236

Let's delve into the technical details of CVE-2023-34236 to understand the vulnerability better.

Vulnerability Description

The vulnerability allows an authenticated remote attacker to access sensitive information printed by functions

tfexec.ShowPlan

,

tfexec.ShowPlanRaw

, and

tfexec.Output

in Weave GitOps Terraform Runner (

tf-runner

). The information leakage could include configurations or tokens that enable unauthorized access.

Affected Systems and Versions

The affected product is Weave GitOps Terraform Controller specifically versions < 0.14.4 and >= 0.15.0-rc.1, < 0.15.0-rc.5. Users on these versions are at risk of exposure to sensitive data.

Exploitation Mechanism

An unauthorized remote attacker can exploit the vulnerability by accessing the sensitive information printed in the pod logs, potentially extracting configurations or tokens to compromise system security.

Mitigation and Prevention

Learn how to mitigate and prevent the risks associated with CVE-2023-34236 below.

Immediate Steps to Take

Users are advised to upgrade to Weave GitOps Terraform Controller versions v0.14.4 or v0.15.0-rc.5 to patch the vulnerability. Additionally, as a temporary fix, users can add the

DISABLE_TF_LOGS

environment variable to tf-runners via the Terraform Custom Resource to prevent the logging of sensitive information.

Long-Term Security Practices

It is essential to regularly update software to the latest patched versions, implement access controls, and follow security best practices to prevent information disclosure vulnerabilities like CVE-2023-34236.

Patching and Updates

Stay informed about security advisories, patches, and updates released by Weave GitOps Terraform Controller to ensure the security of your systems.