November 13, 2026 Follow Egret
CVE-2021-22017 · CVE record: PUBLISHED

VMware vCenter Server Improper Access Control

n/a VMware vCenter Server, VMware Cloud Foundation

Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to bypass proxy leading to internal endpoints being accessed.

Exploitation evidence

Known exploited · CISA KEV listed

Added 2022-01-10. Ransomware campaign use: Unknown.

CISA required action: Apply updates per vendor instructions.

CISA due date: 2022-01-24. This is the catalog’s deadline, not an assessment of your organization’s exposure.

KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗

Reported products and versions

n/a / VMware vCenter Server, VMware Cloud Foundation

Default status: Not specified

  • affected: VMware vCenter Server(6.7 before 6.7 U3o and 6.5 before 6.5 U3q) and VMware Cloud Foundation 3.x before 3.10.2.2

Fixes and workarounds

No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.

Sources and related reporting

CVE Program record ↗ · Download tracked evidence as JSON

Observed change timeline

History begins when Egret first downloads each source. It is not the complete upstream CVE history.

12 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-12",
  "epss": 0.49177,
  "percentile": 0.98902
}
10 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-10",
  "epss": 0.49177,
  "percentile": 0.98895
}
09 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-09",
  "epss": 0.49177,
  "percentile": 0.98893
}
08 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-08",
  "epss": 0.49177,
  "percentile": 0.98892
}
07 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-07",
  "epss": 0.49177,
  "percentile": 0.98892
}
06 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-06",
  "epss": 0.49177,
  "percentile": 0.98891
}
06 Nov 2026, 06:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-05",
  "epss": 0.49177,
  "percentile": 0.98889
}
06 Nov 2026, 00:20 Jerusalem · CVE Program record changed

Stored CNA snapshot at this observation.

{
  "containers": {
    "adp": [
      {
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        "references": [
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              "x_transferred"
            ],
            "url": "https://www.vmware.com/security/advisories/VMSA-2021-0020.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-22017",
                "options": [
                  {
                    "Exploitation": "active"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-01-29T17:54:48.927818Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          },
          {
            "other": {
              "content": {
                "dateAdded": "2022-01-10",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22017"
              },
              "type": "kev"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "description": "CWE-noinfo Not enough information",
                "lang": "en",
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        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-21T23:25:31.570Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "government-resource"
            ],
            "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22017"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2022-01-10T00:00:00.000Z",
            "value": "CVE-2021-22017 added to CISA KEV"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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        }
      ],
      "descriptions": [
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        }
      ],
      "problemTypes": [
        {
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            {
              "description": "Rhttpproxy bypass vulnerability",
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              "type": "text"
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      ],
      "providerMetadata": {
        "dateUpdated": "2021-09-23T12:13:01.000Z",
        "orgId": "dcf2e128-44bd-42ed-91e8-88f912c1401d",
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      },
      "references": [
        {
          "tags": [
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          ],
          "url": "https://www.vmware.com/security/advisories/VMSA-2021-0020.html"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security@vmware.com",
          "ID": "CVE-2021-22017",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
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                      "product_name": "VMware vCenter Server, VMware Cloud Foundation",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "VMware vCenter Server(6.7 before 6.7 U3o and 6.5 before 6.5 U3q) and VMware Cloud Foundation 3.x before 3.10.2.2"
                          }
                        ]
                      }
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        "data_format": "MITRE",
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        "description": {
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            }
          ]
        },
        "problemtype": {
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        },
        "references": {
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            {
              "name": "https://www.vmware.com/security/advisories/VMSA-2021-0020.html",
              "refsource": "MISC",
              "url": "https://www.vmware.com/security/advisories/VMSA-2021-0020.html"
            }
          ]
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    }
  },
  "cveMetadata": {
    "assignerOrgId": "dcf2e128-44bd-42ed-91e8-88f912c1401d",
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    "datePublished": "2021-09-23T12:13:01.000Z",
    "dateReserved": "2021-01-04T00:00:00.000Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}
04 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-04",
  "epss": 0.49177,
  "percentile": 0.98889
}
03 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-03",
  "epss": 0.49177,
  "percentile": 0.98887
}
03 Nov 2026, 02:22 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-02",
  "epss": 0.49177,
  "percentile": 0.98885
}
03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed

Stored KEV snapshot at this observation.

{
  "cveID": "CVE-2021-22017",
  "cwes": [
    "CWE-23"
  ],
  "dateAdded": "2022-01-10",
  "dueDate": "2022-01-24",
  "forensicTriage": "No",
  "knownRansomwareCampaignUse": "Unknown",
  "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-22017",
  "product": "vCenter Server",
  "requiredAction": "Apply updates per vendor instructions.",
  "shortDescription": "Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization.",
  "vendorProject": "VMware",
  "vulnerabilityName": "VMware vCenter Server Improper Access Control"
}
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