How to remediate – VMware Horizon Workspace Detection

1. Introduction

VMware Horizon Workspace Detection identifies instances of the VMware Horizon Workspace web application installed on a remote host. This is a management tool for devices, and its presence indicates potential exposure to vulnerabilities affecting the platform. Successful exploitation could lead to information disclosure or device compromise. Confidentiality, integrity, and availability may be impacted.

2. Technical Explanation

VMware Horizon Workspace is a web application used to manage devices within an organisation. The vulnerability stems from the installation of this application itself, as it represents an attack surface. An attacker would need network access to the host running the application to attempt exploitation. There are no known CVEs associated with simply having the application installed; however, any vulnerabilities discovered in Horizon Workspace could be exploited remotely.

• Root cause: The presence of a web application introduces potential security weaknesses.
• Exploit mechanism: An attacker would scan for and access the Horizon Workspace instance, then attempt to exploit known or future vulnerabilities within the application. For example, they might try to leverage an SQL injection flaw in a login form if one exists.
• Scope: Affected platforms are those running VMware Horizon Workspace. Specific versions depend on the deployment.

3. Detection and Assessment

Confirming whether a system is vulnerable involves checking for the presence of the application. A quick check can identify its installation, while more thorough methods involve reviewing installed software lists.

• Quick checks: Check running services using ps -ef | grep horizon or look for related processes in Task Manager on Windows systems.
• Scanning: Nessus plugin ID 138694 can identify VMware Horizon Workspace installations as an example only.
• Logs and evidence: Application logs may contain references to “Horizon Workspace”. Check the application installation directory (typically under Program Files or /opt).

ps -ef | grep horizon

4. Solution / Remediation Steps

The primary solution is to assess the need for Horizon Workspace and, if not required, uninstall it. If needed, ensure it’s kept up-to-date with security patches.

4.1 Preparation

• Dependencies: None expected. Roll back plan is to restore from the snapshot/backup.
• Change window needs may apply depending on business impact; approval from IT management might be needed.

4.2 Implementation

1. Step 1: Uninstall VMware Horizon Workspace through the operating system’s control panel or package manager (e.g., using ‘apt remove’ on Linux).
2. Step 2: Reboot the system if prompted by the uninstaller.

4.3 Config or Code Example

Before

#Example listing of installed packages (Linux)
dpkg -l | grep horizon

After

#Example listing of installed packages after uninstall (Linux)
dpkg -l | grep horizon #Should return no results.

4.4 Security Practices Relevant to This Vulnerability

Practices that directly address this vulnerability type include minimising the attack surface and maintaining a robust patch cadence.

• Practice 1: Least privilege – limit user access to reduce impact if Horizon Workspace is compromised.
• Practice 2: Patch cadence – regularly update VMware products to address known vulnerabilities.

4.5 Automation (Optional)

#Example PowerShell script to uninstall Horizon Workspace (Windows - use with caution!)
Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -like "*Horizon Workspace*"} | Uninstall-Package

5. Verification / Validation

• Post-fix check: Run ps -ef | grep horizon or check Task Manager on Windows; no related processes should be listed.
• Re-test: Re-run the initial detection method (service check) to confirm Horizon Workspace is no longer present.
• Smoke test: Verify other core system functions are still working as expected.
• Monitoring: Monitor application logs for any unexpected entries related to Horizon Workspace, as an example only.

ps -ef | grep horizon #Should return no results.

6. Preventive Measures and Monitoring

Preventive measures include maintaining a secure baseline configuration and incorporating vulnerability scanning into deployment pipelines.

• Baselines: Update security baselines to exclude unnecessary software like Horizon Workspace if it’s not required.
• Pipelines: Add checks in CI/CD pipelines to identify unauthorized or unexpected software installations.
• Asset and patch process: Implement a regular asset review cycle to identify unused software, and a patch management process for installed applications.

7. Risks, Side Effects, and Roll Back

Uninstalling Horizon Workspace may disrupt dependent services if any exist. The roll back steps involve restoring from the pre-uninstall snapshot/backup.

• Risk or side effect 2: Data loss if configuration data is not backed up.
• Roll back:
  1. Step 1: Restore the system from the pre-uninstall snapshot/backup.
  2. Step 2: Verify Horizon Workspace is restored and functioning correctly.

8. References and Resources

• Vendor advisory or bulletin: https://www.vmware.com/products/workspace-portal.html