CVE-2021-36368
Vulnerability from cvelistv5
Published
2022-03-12 23:24
Modified
2024-08-04 00:54
Severity ?
Summary
An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user's behalf. NOTE: the vendor's position is "this is not an authentication bypass, since nothing is being bypassed.
References
cve@mitre.orghttps://bugzilla.mindrot.org/show_bug.cgi?id=3316Issue Tracking, Third Party Advisory
cve@mitre.orghttps://docs.ssh-mitm.at/trivialauth.htmlThird Party Advisory
cve@mitre.orghttps://github.com/openssh/openssh-portable/pull/258Patch, Third Party Advisory
cve@mitre.orghttps://security-tracker.debian.org/tracker/CVE-2021-36368Third Party Advisory
cve@mitre.orghttps://www.openssh.com/security.htmlVendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.mindrot.org/show_bug.cgi?id=3316Issue Tracking, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://docs.ssh-mitm.at/trivialauth.htmlThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/openssh/openssh-portable/pull/258Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://security-tracker.debian.org/tracker/CVE-2021-36368Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.openssh.com/security.htmlVendor Advisory
Impacted products
Vendor Product Version
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T00:54:51.549Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.openssh.com/security.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/openssh/openssh-portable/pull/258"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://bugzilla.mindrot.org/show_bug.cgi?id=3316"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://docs.ssh-mitm.at/trivialauth.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://security-tracker.debian.org/tracker/CVE-2021-36368"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user\u0027s behalf. NOTE: the vendor\u0027s position is \"this is not an authentication bypass, since nothing is being bypassed."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-04-12T14:45:45",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.openssh.com/security.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/openssh/openssh-portable/pull/258"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://bugzilla.mindrot.org/show_bug.cgi?id=3316"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://docs.ssh-mitm.at/trivialauth.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://security-tracker.debian.org/tracker/CVE-2021-36368"
        }
      ],
      "tags": [
        "disputed"
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-36368",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "** DISPUTED ** An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user\u0027s behalf. NOTE: the vendor\u0027s position is \"this is not an authentication bypass, since nothing is being bypassed.\""
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://www.openssh.com/security.html",
              "refsource": "MISC",
              "url": "https://www.openssh.com/security.html"
            },
            {
              "name": "https://github.com/openssh/openssh-portable/pull/258",
              "refsource": "MISC",
              "url": "https://github.com/openssh/openssh-portable/pull/258"
            },
            {
              "name": "https://bugzilla.mindrot.org/show_bug.cgi?id=3316",
              "refsource": "CONFIRM",
              "url": "https://bugzilla.mindrot.org/show_bug.cgi?id=3316"
            },
            {
              "name": "https://docs.ssh-mitm.at/trivialauth.html",
              "refsource": "MISC",
              "url": "https://docs.ssh-mitm.at/trivialauth.html"
            },
            {
              "name": "https://security-tracker.debian.org/tracker/CVE-2021-36368",
              "refsource": "MISC",
              "url": "https://security-tracker.debian.org/tracker/CVE-2021-36368"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-36368",
    "datePublished": "2022-03-12T23:24:35",
    "dateReserved": "2021-07-09T00:00:00",
    "dateUpdated": "2024-08-04T00:54:51.549Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-36368\",\"sourceIdentifier\":\"cve@mitre.org\",\"published\":\"2022-03-13T00:15:07.937\",\"lastModified\":\"2024-11-21T06:13:36.983\",\"vulnStatus\":\"Modified\",\"cveTags\":[{\"sourceIdentifier\":\"cve@mitre.org\",\"tags\":[\"disputed\"]}],\"descriptions\":[{\"lang\":\"en\",\"value\":\"An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user\u0027s behalf. NOTE: the vendor\u0027s position is \\\"this is not an authentication bypass, since nothing is being bypassed.\"},{\"lang\":\"es\",\"value\":\"** EN DISPUTA ** Se ha detectado un problema en OpenSSH versiones anteriores a 8.9. Si un cliente est\u00e1 usando autenticaci\u00f3n de clave p\u00fablica con reenv\u00edo de agentes pero sin -oLogLevel=verbose, y un atacante ha modificado silenciosamente el servidor para que soporte la opci\u00f3n de autenticaci\u00f3n None, entonces el usuario no puede determinar si la autenticaci\u00f3n FIDO va a confirmar que el usuario desea conectarse a ese servidor, o que el usuario desea permitir que ese servidor sea conectado a un servidor diferente en nombre del usuario. NOTA: la posici\u00f3n del proveedor es que \\\"esto no es una omisi\u00f3n de la autenticaci\u00f3n, ya que no est\u00e1 omiti\u00e9ndose nada\\\"\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N\",\"baseScore\":3.7,\"baseSeverity\":\"LOW\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.2,\"impactScore\":1.4}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:H/Au:N/C:P/I:N/A:N\",\"baseScore\":2.6,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"HIGH\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"PARTIAL\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"baseSeverity\":\"LOW\",\"exploitabilityScore\":4.9,\"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-287\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"8.9\",\"matchCriteriaId\":\"E32FF036-1293-4C11-85EB-ACAD8ACBAC2C\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"DEECE5FC-CACF-4496-A3E7-164736409252\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"07B237A9-69A3-4A9C-9DA0-4E06BD37AE73\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"FA6FEEC2-9F11-4643-8827-749718254FED\"}]}]}],\"references\":[{\"url\":\"https://bugzilla.mindrot.org/show_bug.cgi?id=3316\",\"source\":\"cve@mitre.org\",\"tags\":[\"Issue Tracking\",\"Third Party Advisory\"]},{\"url\":\"https://docs.ssh-mitm.at/trivialauth.html\",\"source\":\"cve@mitre.org\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://github.com/openssh/openssh-portable/pull/258\",\"source\":\"cve@mitre.org\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://security-tracker.debian.org/tracker/CVE-2021-36368\",\"source\":\"cve@mitre.org\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.openssh.com/security.html\",\"source\":\"cve@mitre.org\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://bugzilla.mindrot.org/show_bug.cgi?id=3316\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Third Party Advisory\"]},{\"url\":\"https://docs.ssh-mitm.at/trivialauth.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://github.com/openssh/openssh-portable/pull/258\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://security-tracker.debian.org/tracker/CVE-2021-36368\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.openssh.com/security.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Vendor Advisory\"]}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




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.