VMware vCenter RCE Bug Threat Intel Advisory

Executive Summary

The cSphere Client contains an RCE vulnerability in a vCenter Server plugin. This gives an unauthorized actor the ability to execute arbitrary code on a vCenter Server instance. Which comes with unrestricted privileges on the underlying operating system that hosts the Server.

Technical Details

The vulnerable plugin “vropspluginui” which is part of the vCenter Server exposes critical services without any authorization to any unauthenticated user. The service known as “uploadova” resides in the following location:

/ui/vropspluginui/rest/services/uploadova 

It has an unrestricted upload vulnerability with no input filtering which leads to an arbitrary file upload. The uploaded file has the same security descriptor of the server instance and has write access to internal directories. An unauthorized threat actor can remotely upload a malicious file that executes input supplied by the attacker on the remote server leading to RCE.

Impact 

• A threat actor with the network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.
• A threat actor can use the compromised server as a foothold to further the attack deep inside the target network.

Mitigations

Update the affected versions to their respective patched versions.

Official documentation: https://www.vmware.com/security/advisories/VMSA-2021-0002.html