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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
CRITICAL 9.8
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.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-21972 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-21972

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2021-21972 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-21972

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.