How to remediate – VMware vCenter Data Collection

1. Introduction

The VMware vCenter Data Collection vulnerability involves collecting all data from VMware vCenter using its REST APIs. This allows an attacker to gather sensitive information about a virtualised environment, potentially leading to further compromise of the infrastructure. Systems running VMware vCenter are usually affected. A successful exploit could impact confidentiality, integrity and availability of the virtualised systems.

2. Technical Explanation

This vulnerability allows unauthenticated access to data within vCenter via its REST APIs. An attacker can retrieve host information from a targeted VMware vCenter host. No specific CVE is currently associated with this issue, but it represents an information disclosure risk. For example, an attacker could use the API to enumerate all hosts and their configurations.

• Root cause: The REST APIs do not enforce sufficient authentication or authorisation controls for data collection.
• Exploit mechanism: An attacker sends requests to the vCenter REST API endpoints to retrieve host data. A simple HTTP GET request can be used to access information.
• Scope: VMware vCenter versions are affected, specific versions have not been identified in this report.

3. Detection and Assessment

Confirming vulnerability involves checking the version of vCenter and verifying API accessibility. A quick check is to see if the REST APIs respond without authentication. A thorough method would involve attempting to retrieve host data via the API.

• Quick checks: Check the vCenter web UI for the installed version.
• Scanning: Nessus plugin ID 168942 may identify this issue as an example only.
• Logs and evidence: Review vCenter logs for suspicious API activity, particularly requests to data collection endpoints.

curl -k https://your_vcenter_ip/api/version

4. Solution / Remediation Steps

Fixing this issue requires securing access to the vCenter REST APIs. The following steps outline how to achieve this.

4.1 Preparation

• Ensure you have administrator credentials for vCenter. A roll back plan is to restore from the snapshot taken earlier.
• A change window may be needed, and approval from the security team should be obtained.

4.2 Implementation

1. Step 1: Enable authentication for all REST API endpoints within vCenter settings.
2. Step 2: Configure role-based access control (RBAC) to restrict data collection permissions to authorized users only.
3. Step 3: Review firewall rules to limit external access to the vCenter APIs.

4.3 Config or Code Example

Before

# API Access: Unrestricted

After

# API Access: Authentication Required, RBAC Enabled

4.4 Security Practices Relevant to This Vulnerability

Several security practices directly address this vulnerability type. Least privilege reduces the impact if exploited. Input validation can block unsafe data requests. Secure defaults ensure APIs are not open by default.

• Practice 1: Implement least privilege access control to limit who can access sensitive data.
• Practice 2: Enable input validation on all API endpoints to prevent malicious requests.

4.5 Automation (Optional)

# Example PowerShell Script to check API access
# Requires VMware PowerCLI module
# Connect-VIServer -Server your_vcenter_ip -User administrator -Password password
# Get-VIComponent -Identity $esxhost | Where-Object {$_.Name -like "*API*"}

5. Verification / Validation

Confirming the fix involves verifying API access requires authentication and that data collection is restricted to authorized users. Run the earlier detection command again, expecting an authentication error. Perform a simple service smoke test by logging into vCenter.

• Post-fix check: `curl -k https://your_vcenter_ip/api/version` should return an authentication error (e.g., 401 Unauthorized).
• Re-test: Re-run the earlier detection command to confirm it now requires authentication.
• Smoke test: Verify you can log into the vCenter web UI with a valid administrator account.
• Monitoring: Monitor vCenter logs for failed API access attempts, indicating potential brute force attacks.

curl -k https://your_vcenter_ip/api/version

6. Preventive Measures and Monitoring

Update security baselines to include API authentication requirements. Add checks in CI or deployment pipelines to ensure APIs are not exposed without protection. Implement a regular patch or config review cycle.

• Baselines: Update your VMware vCenter security baseline to require API authentication.
• Pipelines: Include SAST and SCA tools in your CI/CD pipeline to identify insecure configurations.

7. Risks, Side Effects, and Roll Back

Enabling authentication may cause compatibility issues with older applications that do not support it. Incorrect RBAC configuration could lock out legitimate users. Restore from the snapshot taken earlier if any issues occur.

• Risk or side effect 1: Compatibility issues with legacy integrations. Mitigation is to update those integrations.
• Risk or side effect 2: Potential lockout of users due to incorrect RBAC settings. Mitigation is to carefully plan and test RBAC changes.

8. References and Resources

• Vendor advisory or bulletin: [https://www.vmware.com/security/advisories](https://www.vmware.com/security/advisories)
• NVD or CVE entry: No specific CVE currently available for this issue.
• Product or platform documentation relevant to the fix: [https://docs.vmware.com/en/VMware-vSphere/index.html](https://docs.vmware.com/en/VMware-vSphere/index.html)