Alert - Active exploitation of VMware vulnerability

Number: AL20-027
Date: 7 December 2020


This Alert is intended for IT professionals and managers of notified organizations.


An Alert is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide additional detection and mitigation advice to recipients. The Canadian Centre for Cyber Security ("Cyber Centre") is also available to provide additional assistance regarding the content of this Alert to recipients as requested.


On 7 December the Cyber Centre was made aware of active exploitation of a VMware command injection vulnerability (CVE-2020-4006) using stolen credentials [1], which are frequently used to exploit systems [2]. A malicious actor with network access to the administrative configurator on port 8443 and a valid password for the configurator admin account can execute commands with unrestricted privileges on the underlying operating system [3]. The list of vulnerable products includes VMware Workspace One Access, Access Connector, Identity Manager, and Identity Manager Connector.


The Cyber Centre recommends the following actions to detect potentially malicious activity against vulnerable systems:

  • Monitor for any unusual connections to the administrative configurator on port 8443;
  • Examine system logs for unusual or unauthorized activity;
  • Check for recently added users with elevated privileges.


The Cyber Centre recommends that organizations follow mitigation and patching recommendations for any impacted products:

  • Apply recommended patches for affected products [4];
  • Ensure the administrative configurator is not accessible to external interfaces;
  • Enable Two-Factor Authentication [5];
  • Apply workaround solutions as a temporary measure for CVE-2020-4006 [6] until patching is completed.

Should organizations identify associated activity to that described in this Alert, recipients are encouraged to contact the Cyber Centre by email ( or by telephone (1-833-CYBER-88 or 1-833-292-3788).


[1] Russian State-Sponsored Malicious Cyber Actors Exploit Known Vulnerability in Virtual Workspaces

[2] Canadian organizations exploited via unpatched devices and inadequate authentication

[3] VMware Advisory ID: VMSA-2020-0027.2

[4] HW-128524: CVE-2020-4006 Patches for Workspace ONE Access, Identity Manager and Connector (81754)

[5] VMware Workspace ONE Access: Configuring VMware Verify for Two-Factor Authentication

[6] VMware Workspace ONE Access, VMware Identity Manager, VMware Identity Manager Connector Workaround Instructions for CVE-2020-4006 (81731)

[7] VMware Security Advisory


The Canadian Centre for Cyber Security (Cyber Centre) operates as part of the Communications Security Establishment. We are Canada's national authority on cyber security and we lead the government's response to cyber security events. As Canada's national computer security incident response team, the Cyber Centre works in close collaboration with government departments, critical infrastructure, Canadian businesses and international partners to prepare for, respond to, mitigate, and recover from cyber events. We do this by providing authoritative advice and support, and coordinating information sharing and incident response. The Cyber Centre is outward-facing, welcoming partnerships that help build a stronger, more resilient cyber space in Canada.

The Cyber Centre can be contacted at:


Toll Free: 1-833-CYBER-88 (1-833-292-3788)

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