CVE-2021-21972

VMware vCenter Server Remote Code Execution Vulnerability

  • Critical 9.8
  • Exploited: added to CISA KEV 3 Nov 2021
  • Used in ransomware campaigns

Description

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).

Key facts

Published
24 Feb 2021
Last changed
12 Aug 2026
Assigned by
vmware
KEV added
3 Nov 2021
KEV fix due
17 Nov 2021
Used in ransomware
Yes, according to CISA
EPSS
99.865% likely to be exploited in the next 30 days, higher than 99.963% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: active; Automatable: yes; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 9.8CVSS 3.1, Criticalfrom CISA (ADP container)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What to do

  • Apply updates per vendor instructions.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
n/aVMware vCenter Server
  • 7.x before 7.0 U1c (affected)
  • 6.7 before 6.7 U3l (affected)
  • 6.5 before 6.5 U3n (affected)
n/aVMware Cloud Foundation
  • 4.x before 4.2 (affected)
  • 3.x before 3.10.1.2 (affected)

Timeline

  1. 24 Feb 2021 Published
  2. 3 Nov 2021 CVE-2021-21972 added to CISA KEV
  3. 3 Nov 2021 Added to the CISA KEV catalogue

Weakness

Practice this bug class

HackZoneLabs has a hands-on lab on Path traversal (CWE-22).

References