Proof-of-concept exploit scripts for a critical remote code execution flaw, along with mass scanning activity, indicate that organizations should apply vCenter Server patches immediately. Update May 26: The Proof of concept section has been updated to reflect the publication of a proof-of-concept (PoC) for CVE-2021-21974.

CVE-2021-21972: VMware vCenter Server Remote Code Execution Vulnerability

The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

The version of VMware vCenter Server installed on the remote host is 6.5 prior to 6.5 U3n, 6.7 prior to 6.7 U3l or 7.0 prior to 7.0 U1c. It is, therefore, affected by multiple vulnerabilities, as follows:

  - The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. A malicious     actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the     underlying operating system that hosts vCenter Server. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7     before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).
    (CVE-2021-21972)

  - The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation     of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by     sending a POST request to vCenter Server plugin leading to information disclosure. This affects: VMware vCenter     Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2     and 3.x before 3.10.1.2). (CVE-2021-21973)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version   number. Nessus has also not tested for the presence of a workaround.

ID	Name	Product	Family	Severity
113243	VMware vCenter Server 6.5 < 6.5 U3n / 6.7 < 6.7 U3l / 7.0 < 7.0 U1c Remote Code Execution	Web App Scanning	Component Vulnerability	critical
146826	VMware vCenter Server 6.5 / 6.7 / 7.0 Multiple Vulnerabilities (VMSA-2021-0002)	Nessus	Misc.	critical
146825	VMware vCenter Server RCE (direct check)	Nessus	Misc.	critical

Detections

Analytics

CVE-2021-21972

critical

Tenable Plugins

critical

critical

critical