cve-2021-39155
Vulnerability from cvelistv5
Published
2021-08-24 22:25
Modified
2024-08-04 01:58
Summary
Authorization Policy Bypass Due to Case Insensitive Host Comparison
Impacted products
istioistio
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T01:58:18.140Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://datatracker.ietf.org/doc/html/rfc4343"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "istio",
          "vendor": "istio",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 1.9.8"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.10.0, \u003c 1.10.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.11.0, \u003c 1.11.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. According to [RFC 4343](https://datatracker.ietf.org/doc/html/rfc4343), Istio authorization policy should compare the hostname in the HTTP Host header in a case insensitive way, but currently the comparison is case sensitive. The proxy will route the request hostname in a case-insensitive way which means the authorization policy could be bypassed. As an example, the user may have an authorization policy that rejects request with hostname \"httpbin.foo\" for some source IPs, but the attacker can bypass this by sending the request with hostname \"Httpbin.Foo\". Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize Host header before the authorization check. This is similar to the Path normalization presented in the [Security Best Practices](https://istio.io/latest/docs/ops/best-practices/security/#case-normalization) guide."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 8.3,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-178",
              "description": "CWE-178: Improper Handling of Case Sensitivity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-08-24T22:25:17",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://datatracker.ietf.org/doc/html/rfc4343"
        }
      ],
      "source": {
        "advisory": "GHSA-7774-7vr3-cc8j",
        "discovery": "UNKNOWN"
      },
      "title": "Authorization Policy Bypass Due to Case Insensitive Host Comparison",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-39155",
          "STATE": "PUBLIC",
          "TITLE": "Authorization Policy Bypass Due to Case Insensitive Host Comparison"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "istio",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "\u003c= 1.9.8"
                          },
                          {
                            "version_value": "\u003e= 1.10.0, \u003c 1.10.4"
                          },
                          {
                            "version_value": "\u003e= 1.11.0, \u003c 1.11.1"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "istio"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. According to [RFC 4343](https://datatracker.ietf.org/doc/html/rfc4343), Istio authorization policy should compare the hostname in the HTTP Host header in a case insensitive way, but currently the comparison is case sensitive. The proxy will route the request hostname in a case-insensitive way which means the authorization policy could be bypassed. As an example, the user may have an authorization policy that rejects request with hostname \"httpbin.foo\" for some source IPs, but the attacker can bypass this by sending the request with hostname \"Httpbin.Foo\". Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize Host header before the authorization check. This is similar to the Path normalization presented in the [Security Best Practices](https://istio.io/latest/docs/ops/best-practices/security/#case-normalization) guide."
            }
          ]
        },
        "impact": {
          "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 8.3,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-178: Improper Handling of Case Sensitivity"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j",
              "refsource": "CONFIRM",
              "url": "https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j"
            },
            {
              "name": "https://datatracker.ietf.org/doc/html/rfc4343",
              "refsource": "MISC",
              "url": "https://datatracker.ietf.org/doc/html/rfc4343"
            }
          ]
        },
        "source": {
          "advisory": "GHSA-7774-7vr3-cc8j",
          "discovery": "UNKNOWN"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-39155",
    "datePublished": "2021-08-24T22:25:18",
    "dateReserved": "2021-08-16T00:00:00",
    "dateUpdated": "2024-08-04T01:58:18.140Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-39155\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2021-08-24T23:15:07.093\",\"lastModified\":\"2024-02-21T21:01:31.320\",\"vulnStatus\":\"Analyzed\",\"descriptions\":[{\"lang\":\"en\",\"value\":\"Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. According to [RFC 4343](https://datatracker.ietf.org/doc/html/rfc4343), Istio authorization policy should compare the hostname in the HTTP Host header in a case insensitive way, but currently the comparison is case sensitive. The proxy will route the request hostname in a case-insensitive way which means the authorization policy could be bypassed. As an example, the user may have an authorization policy that rejects request with hostname \\\"httpbin.foo\\\" for some source IPs, but the attacker can bypass this by sending the request with hostname \\\"Httpbin.Foo\\\". Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize Host header before the authorization check. This is similar to the Path normalization presented in the [Security Best Practices](https://istio.io/latest/docs/ops/best-practices/security/#case-normalization) guide.\"},{\"lang\":\"es\",\"value\":\"Istio es una plataforma de c\u00f3digo abierto que proporciona una forma uniforme de integrar microservicios, administrar el flujo de tr\u00e1fico entre microservicios, aplicar pol\u00edticas y agregar datos de telemetr\u00eda. Seg\u00fan [RFC 4343](https://datatracker.ietf.org/doc/html/rfc4343), la pol\u00edtica de autorizaci\u00f3n de Istio deber\u00eda comparar el nombre de host en el encabezado HTTP Host de forma no sensible a may\u00fasculas y min\u00fasculas, pero actualmente la comparaci\u00f3n es sensible a may\u00fasculas y min\u00fasculas. El proxy enrutar\u00e1 el nombre de host de la petici\u00f3n de forma no sensible a may\u00fasculas y min\u00fasculas, lo que significa que la pol\u00edtica de autorizaci\u00f3n podr\u00eda ser omitida. Por ejemplo, el usuario puede tener una pol\u00edtica de autorizaci\u00f3n que rechace peticiones con el nombre de host \\\"httpbin.foo\\\" para algunas IPs de origen, pero el atacante puede omitir esto mediante el env\u00edo de la petici\u00f3n con el nombre de host \\\"Httpbin.Foo\\\". Los parches est\u00e1n disponibles en Istio versi\u00f3n 1.11.1, Istio versi\u00f3n 1.10.4 e Istio versi\u00f3n 1.9.8. Como soluci\u00f3n, puede escribirse un filtro Lua para normalizar el encabezado Host antes de la comprobaci\u00f3n de la autorizaci\u00f3n. Esto es similar a la normalizaci\u00f3n de la Ruta presentada en la gu\u00eda [Security Best Practices](https://istio.io/latest/docs/ops/best-practices/security/#case-normalization).\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6},{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"LOW\",\"baseScore\":8.3,\"baseSeverity\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.5}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:L/Au:N/C:P/I:N/A:N\",\"accessVector\":\"NETWORK\",\"accessComplexity\":\"LOW\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"PARTIAL\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\",\"baseScore\":5.0},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":10.0,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-178\"},{\"lang\":\"en\",\"value\":\"CWE-863\"}]},{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-178\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.9.8\",\"matchCriteriaId\":\"2FBF48C6-1E39-4692-A652-27E7DCDC81BC\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"1.10.0\",\"versionEndExcluding\":\"1.10.4\",\"matchCriteriaId\":\"59BD6BCF-15CE-49D9-B487-EEA603D3D5CC\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"1.11.0\",\"versionEndExcluding\":\"1.11.1\",\"matchCriteriaId\":\"886DF572-26C9-4BC9-875F-F043D445C346\"}]}]}],\"references\":[{\"url\":\"https://datatracker.ietf.org/doc/html/rfc4343\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Third Party Advisory\"]}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading...

Loading...

Loading...

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.