cve-2021-21274
Vulnerability from cvelistv5
Published
2021-02-26 17:25
Modified
2024-08-03 18:09
Summary
Denial of service attack via .well-known lookups
Impacted products
Vendor Product Version
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T18:09:15.070Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/matrix-org/synapse/releases/tag/v1.25.0"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/matrix-org/synapse/pull/8950"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6"
          },
          {
            "name": "FEDORA-2021-a627cfd31e",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "synapse",
          "vendor": "matrix-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e=0.99.0, \u003c 1.25.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.25.0, a malicious homeserver could redirect requests to their .well-known file to a large file. This can lead to a denial of service attack where homeservers will consume significantly more resources when requesting the .well-known file of a malicious homeserver. This affects any server which accepts federation requests from untrusted servers. Issue is resolved in version 1.25.0. As a workaround the `federation_domain_whitelist` setting can be used to restrict the homeservers communicated with over federation."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400 Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-08-02T02:06:23",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/matrix-org/synapse/releases/tag/v1.25.0"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/matrix-org/synapse/pull/8950"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6"
        },
        {
          "name": "FEDORA-2021-a627cfd31e",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
        }
      ],
      "source": {
        "advisory": "GHSA-2hwx-mjrm-v3g8",
        "discovery": "UNKNOWN"
      },
      "title": "Denial of service attack via .well-known lookups",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-21274",
          "STATE": "PUBLIC",
          "TITLE": "Denial of service attack via .well-known lookups"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "synapse",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "\u003e=0.99.0, \u003c 1.25.0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "matrix-org"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.25.0, a malicious homeserver could redirect requests to their .well-known file to a large file. This can lead to a denial of service attack where homeservers will consume significantly more resources when requesting the .well-known file of a malicious homeserver. This affects any server which accepts federation requests from untrusted servers. Issue is resolved in version 1.25.0. As a workaround the `federation_domain_whitelist` setting can be used to restrict the homeservers communicated with over federation."
            }
          ]
        },
        "impact": {
          "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-400 Uncontrolled Resource Consumption"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8",
              "refsource": "CONFIRM",
              "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8"
            },
            {
              "name": "https://github.com/matrix-org/synapse/releases/tag/v1.25.0",
              "refsource": "MISC",
              "url": "https://github.com/matrix-org/synapse/releases/tag/v1.25.0"
            },
            {
              "name": "https://github.com/matrix-org/synapse/pull/8950",
              "refsource": "MISC",
              "url": "https://github.com/matrix-org/synapse/pull/8950"
            },
            {
              "name": "https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6",
              "refsource": "MISC",
              "url": "https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6"
            },
            {
              "name": "FEDORA-2021-a627cfd31e",
              "refsource": "FEDORA",
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
            }
          ]
        },
        "source": {
          "advisory": "GHSA-2hwx-mjrm-v3g8",
          "discovery": "UNKNOWN"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-21274",
    "datePublished": "2021-02-26T17:25:16",
    "dateReserved": "2020-12-22T00:00:00",
    "dateUpdated": "2024-08-03T18:09:15.070Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-21274\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2021-02-26T18:15:12.237\",\"lastModified\":\"2023-11-07T03:29:42.630\",\"vulnStatus\":\"Modified\",\"descriptions\":[{\"lang\":\"en\",\"value\":\"Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.25.0, a malicious homeserver could redirect requests to their .well-known file to a large file. This can lead to a denial of service attack where homeservers will consume significantly more resources when requesting the .well-known file of a malicious homeserver. This affects any server which accepts federation requests from untrusted servers. Issue is resolved in version 1.25.0. As a workaround the `federation_domain_whitelist` setting can be used to restrict the homeservers communicated with over federation.\"},{\"lang\":\"es\",\"value\":\"Synapse es un servidor dom\u00e9stico de referencia de Matrix escrito en python (paquete pypi matrix-synapse).\u0026#xa0;Matrix es un ecosistema para VoIP y mensajer\u00eda instant\u00e1nea federada abierta.\u0026#xa0;En Synapse versiones anteriores a 1.25.0, un servidor dom\u00e9stico malicioso pod\u00eda redireccionar las peticiones para su archivo .well-known a un archivo grande.\u0026#xa0;Esto puede conllevar a un ataque de denegaci\u00f3n de servicio en el que los servidores dom\u00e9sticos consumir\u00e1n significativamente m\u00e1s recursos al solicitar el archivo .well-known de un servidor dom\u00e9stico malicioso.\u0026#xa0;Esto afecta a cualquier servidor que acepte peticiones de federaci\u00f3n desde servidores que no sean confiables.\u0026#xa0;El problema es resuelto en versi\u00f3n 1.25.0.\u0026#xa0;Como soluci\u00f3n alternativa, el ajuste de \\\"federation_domain_whitelist\\\" puede ser usado para restringir los servidores dom\u00e9sticos que se comunican con la federaci\u00f3n\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\",\"baseScore\":6.5,\"baseSeverity\":\"MEDIUM\"},\"exploitabilityScore\":2.8,\"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:N/I:N/A:L\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"LOW\",\"baseScore\":4.3,\"baseSeverity\":\"MEDIUM\"},\"exploitabilityScore\":2.8,\"impactScore\":1.4}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:M/Au:N/C:N/I:N/A:P\",\"accessVector\":\"NETWORK\",\"accessComplexity\":\"MEDIUM\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"PARTIAL\",\"baseScore\":4.3},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":8.6,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":true}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-770\"}]},{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-400\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"0.99.0\",\"versionEndExcluding\":\"1.25.0\",\"matchCriteriaId\":\"6C16EE11-380E-400F-9A55-6068AAF132D8\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"A930E247-0B43-43CB-98FF-6CE7B8189835\"}]}]}],\"references\":[{\"url\":\"https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/matrix-org/synapse/pull/8950\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/matrix-org/synapse/releases/tag/v1.25.0\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}


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.