CVE-2021-20238

{
  "id": "CVE-2021-20238",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 4.3,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:N/A:N",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8.6,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 3.7,
          "attackVector": "NETWORK",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.2
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "openshift/machine-config-operator",
          "versions": [
            {
              "status": "affected",
              "version": "affecting versions up to, including ose-machine-config-operator-container-v4.9.0"
            }
          ]
        }
      ]
    }
  ],
  "published": "2022-04-01T23:15:08.727",
  "references": [
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1926568",
      "tags": [
        "Issue Tracking",
        "Mitigation",
        "Vendor Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1926568",
      "tags": [
        "Issue Tracking",
        "Mitigation",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "It was found in OpenShift Container Platform 4 that ignition config, served by the Machine Config Server, can be accessed externally from clusters without authentication. The MCS endpoint (port 22623) provides ignition configuration used for bootstrapping Nodes and can include some sensitive data, e.g. registry pull secrets. There are two scenarios where this data can be accessed. The first is on Baremetal, OpenStack, Ovirt, Vsphere and KubeVirt deployments which do not have a separate internal API endpoint and allow access from outside the cluster to port 22623 from the standard OpenShift API Virtual IP address. The second is on cloud deployments when using unsupported network plugins, which do not create iptables rules that prevent to port 22623. In this scenario, the ignition config is exposed to all pods within the cluster and cannot be accessed externally."
    },
    {
      "lang": "es",
      "value": "Se ha encontrado en OpenShift Container Platform 4 que la configuración de encendido, servida por el Machine Config Server, puede ser accedida externamente desde los clusters sin autenticación. El endpoint del MCS (puerto 22623) proporciona la configuración de ignición usada para el arranque de los nodos y puede incluir algunos datos confidenciales, por ejemplo, secretos de extracción del registro. Se presentan dos escenarios en los que puede accederse a estos datos. El primero es en los despliegues de Baremetal, OpenStack, Ovirt, Vsphere y KubeVirt que no presentan un endpoint de API interno separado y permiten el acceso desde fuera del clúster al puerto 22623 desde la dirección IP virtual de la API estándar de OpenShift. La segunda es en los despliegues en la nube cuando son usados plugins de red no soportados, que no crean reglas iptables que impidan al puerto 22623. En este escenario, la configuración de encendido está expuesta a todos los pods dentro del clúster y no puede accederse externamente"
    }
  ],
  "lastModified": "2026-06-17T03:33:31.673",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "932D137F-528B-4526-9A89-CD59FA1AB0FE"
            },
            {
              "criteria": "cpe:2.3:a:redhat:openshift_machine-config-operator:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3548B998-6051-40A8-9F7B-6ABD7973FDD8",
              "versionEndIncluding": "4.9.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}