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PatchSiren cyber security CVE debrief

CVE-2021-21972 VMware CVE debrief

CVE-2021-21972 is a VMware vCenter Server remote code execution vulnerability that CISA added to the Known Exploited Vulnerabilities catalog on 2021-11-03. CISA also marks it as associated with known ransomware campaign use, which makes this a high-priority remediation item for any environment running vCenter Server.

Vendor
VMware
Product
vCenter Server
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

VMware vCenter Server administrators, infrastructure and virtualization teams, patch-management owners, SOC analysts, and incident responders should treat this as urgent.

Technical summary

The official source material identifies this issue as a VMware vCenter Server remote code execution vulnerability. CISA lists it in the KEV catalog, indicating known exploitation, and notes known ransomware campaign use. The documented remediation is to apply updates per vendor instructions.

Defensive priority

Urgent. KEV-listed vulnerabilities with known ransomware campaign use should be prioritized for immediate remediation and validation against the CISA due date of 2021-11-17.

Recommended defensive actions

  • Identify all VMware vCenter Server instances in the environment.
  • Apply VMware updates and follow vendor remediation guidance as soon as possible.
  • Confirm whether any vCenter Server systems are exposed in sensitive or high-value environments.
  • Review authentication, access, and administrative activity around vCenter Server for suspicious behavior.
  • Use the CISA KEV catalog and your patch SLA process to verify remediation before the due date.

Evidence notes

This debrief is based on the supplied CISA KEV source item and the official resource links provided. Supported facts include the product (VMware vCenter Server), vulnerability category (remote code execution), KEV status, date added (2021-11-03), due date (2021-11-17), and known ransomware campaign use. No additional exploitation details are asserted.

Official resources

CISA added CVE-2021-21972 to the Known Exploited Vulnerabilities catalog on 2021-11-03 and assigned a remediation due date of 2021-11-17. The entry also indicates known ransomware campaign use.