{
  "id": "CVE-2021-21973",
  "url": "https://spydr.io/cve/CVE-2021-21973",
  "published": "2021-02-24T17:15:15.923Z",
  "modified": "2026-06-17T03:36:28.910Z",
  "score": 5.3,
  "severity": "medium",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
  "score_source": "NVD",
  "epss": 0.88012,
  "epss_percentile": 0.99763,
  "exploited": true,
  "kev": {
    "added": "2022-03-07",
    "due": "2022-03-21",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Unknown",
    "name": "VMware vCenter Server and Cloud Foundation Server Side Request Forgery (SSRF) Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-21973"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "vmware"
  ],
  "products": [
    "VMware vCenter Server",
    "VMware Cloud Foundation"
  ],
  "cwes": [
    "CWE-918"
  ],
  "description": "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).",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 5.3,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://www.vmware.com/security/advisories/VMSA-2021-0002.html",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21973",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21973",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}