gsd-2020-8562
Vulnerability from gsd
Modified
2023-12-13 01:21
Details
As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.
Aliases
Aliases
CVE-2020-8562


To clipboard 

{
  "GSD": {
    "alias": "CVE-2020-8562",
    "description": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.",
    "id": "GSD-2020-8562",
    "references": [
      "https://www.suse.com/security/cve/CVE-2020-8562.html",
      "https://security.archlinux.org/CVE-2020-8562"
    ]
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2020-8562"
      ],
      "details": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.",
      "id": "GSD-2020-8562",
      "modified": "2023-12-13T01:21:53.364157Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
    "cve.org": {
      "CVE_data_meta": {
        "ASSIGNER": "security@kubernetes.io",
        "DATE_PUBLIC": "2021-05-04T16:51:00.000Z",
        "ID": "CVE-2020-8562",
        "STATE": "PUBLIC",
        "TITLE": "Bypass of Kubernetes API Server proxy TOCTOU"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "Kubernetes",
                    "version": {
                      "version_data": [
                        {
                          "version_affected": "\u003c=",
                          "version_value": "v1.18.18"
                        },
                        {
                          "version_affected": "?\u003e",
                          "version_value": "v1.18.18"
                        },
                        {
                          "version_affected": "\u003c=",
                          "version_value": "v1.19.10"
                        },
                        {
                          "version_affected": "?\u003e",
                          "version_value": "v1.19.10"
                        },
                        {
                          "version_affected": "\u003c=",
                          "version_value": "v1.20.6"
                        },
                        {
                          "version_affected": "?\u003e",
                          "version_value": "v1.20.6"
                        },
                        {
                          "version_affected": "\u003c=",
                          "version_value": "v1.21.0"
                        },
                        {
                          "version_affected": "?\u003e",
                          "version_value": "v1.21.0"
                        }
                      ]
                    }
                  }
                ]
              },
              "vendor_name": "Kubernetes"
            }
          ]
        }
      },
      "credit": [
        {
          "lang": "eng",
          "value": "Javier Provecho"
        }
      ],
      "data_format": "MITRE",
      "data_type": "CVE",
      "data_version": "4.0",
      "description": {
        "description_data": [
          {
            "lang": "eng",
            "value": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane."
          }
        ]
      },
      "generator": {
        "engine": "Vulnogram 0.0.9"
      },
      "impact": {
        "cvss": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 2.2,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        }
      },
      "problemtype": {
        "problemtype_data": [
          {
            "description": [
              {
                "lang": "eng",
                "value": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://github.com/kubernetes/kubernetes/issues/101493",
            "refsource": "MISC",
            "url": "https://github.com/kubernetes/kubernetes/issues/101493"
          },
          {
            "name": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY",
            "refsource": "MISC",
            "url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"
          },
          {
            "name": "https://security.netapp.com/advisory/ntap-20220225-0002/",
            "refsource": "CONFIRM",
            "url": "https://security.netapp.com/advisory/ntap-20220225-0002/"
          }
        ]
      },
      "source": {
        "defect": [
          "https://github.com/kubernetes/kubernetes/issues/101493"
        ],
        "discovery": "EXTERNAL"
      },
      "work_around": [
        {
          "lang": "eng",
          "value": "If this issue affects your clusters\u2019 control planes, you can use dnsmasq for name resolution and configure the min-cache-ttl and neg-ttl parameters to a low non-zero value to enforce cached replies for proxied connections"
        }
      ]
    },
    "gitlab.com": {
      "advisories": [
        {
          "affected_range": "\u003e=1.21.0 \u003c1.21.1||\u003e=1.20.0 \u003c1.20.7||\u003e=1.19.0 \u003c1.19.11||\u003c1.18.19",
          "affected_versions": "All versions starting from 1.21.0 before 1.21.1, all versions starting from 1.20.0 before 1.20.7, all versions starting from 1.19.0 before 1.19.11, all versions before 1.18.19",
          "cvss_v2": "AV:N/AC:M/Au:S/C:P/I:N/A:N",
          "cvss_v3": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "cwe_ids": [
            "CWE-1035",
            "CWE-367",
            "CWE-937"
          ],
          "date": "2022-02-11",
          "description": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.",
          "fixed_versions": [
            "1.21.1",
            "1.21.1",
            "1.19.11",
            "1.18.19",
            "1.18.19"
          ],
          "identifier": "CVE-2020-8562",
          "identifiers": [
            "GHSA-qh36-44jv-c8xj",
            "CVE-2020-8562"
          ],
          "not_impacted": "All versions before 1.21.0, all versions starting from 1.21.1, all versions before 1.20.0, all versions starting from 1.20.7, all versions before 1.19.0, all versions starting from 1.18.19 before 1.19.11",
          "package_slug": "go/k8s.io/kubernetes",
          "pubdate": "2022-02-02",
          "solution": "Upgrade to versions 1.21.1, 1.21.1, 1.19.11, 1.18.19, 1.18.19 or above.",
          "title": "Time-of-check Time-of-use (TOCTOU) Race Condition",
          "urls": [
            "https://nvd.nist.gov/vuln/detail/CVE-2020-8562",
            "https://github.com/kubernetes/kubernetes/issues/101493",
            "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY",
            "https://github.com/advisories/GHSA-qh36-44jv-c8xj"
          ],
          "uuid": "1b421428-da20-49dc-8920-6d0473cc8e4b"
        }
      ]
    },
    "nvd.nist.gov": {
      "configurations": {
        "CVE_data_version": "4.0",
        "nodes": [
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*",
                "cpe_name": [],
                "versionEndIncluding": "1.18.18",
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*",
                "cpe_name": [],
                "versionEndIncluding": "1.19.10",
                "versionStartIncluding": "1.19.0",
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*",
                "cpe_name": [],
                "versionEndIncluding": "1.20.6",
                "versionStartIncluding": "1.20.0",
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:a:kubernetes:kubernetes:1.21.0:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              }
            ],
            "operator": "OR"
          }
        ]
      },
      "cve": {
        "CVE_data_meta": {
          "ASSIGNER": "security@kubernetes.io",
          "ID": "CVE-2020-8562"
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "en",
              "value": "As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "en",
                  "value": "CWE-367"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY",
              "refsource": "MISC",
              "tags": [
                "Mailing List",
                "Third Party Advisory"
              ],
              "url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"
            },
            {
              "name": "https://github.com/kubernetes/kubernetes/issues/101493",
              "refsource": "MISC",
              "tags": [
                "Issue Tracking",
                "Mitigation",
                "Third Party Advisory"
              ],
              "url": "https://github.com/kubernetes/kubernetes/issues/101493"
            },
            {
              "name": "https://security.netapp.com/advisory/ntap-20220225-0002/",
              "refsource": "CONFIRM",
              "tags": [
                "Third Party Advisory"
              ],
              "url": "https://security.netapp.com/advisory/ntap-20220225-0002/"
            }
          ]
        }
      },
      "impact": {
        "baseMetricV2": {
          "acInsufInfo": false,
          "cvssV2": {
            "accessComplexity": "MEDIUM",
            "accessVector": "NETWORK",
            "authentication": "SINGLE",
            "availabilityImpact": "NONE",
            "baseScore": 3.5,
            "confidentialityImpact": "PARTIAL",
            "integrityImpact": "NONE",
            "vectorString": "AV:N/AC:M/Au:S/C:P/I:N/A:N",
            "version": "2.0"
          },
          "exploitabilityScore": 6.8,
          "impactScore": 2.9,
          "obtainAllPrivilege": false,
          "obtainOtherPrivilege": false,
          "obtainUserPrivilege": false,
          "severity": "LOW",
          "userInteractionRequired": false
        },
        "baseMetricV3": {
          "cvssV3": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.1,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 1.6,
          "impactScore": 1.4
        }
      },
      "lastModifiedDate": "2022-03-29T16:35Z",
      "publishedDate": "2022-02-01T11:15Z"
    }
  }
}


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