CVE-2021-20254 (GCVE-0-2021-20254)

Vulnerability from cvelistv5 – Published: 2021-05-05 13:36 – Updated: 2024-08-03 17:37
VLAI
Summary
A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity.
Severity
6.8 (Medium)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CWE
Assigner
References
Impacted products
Vendor Product Version
n/a samba Affected: samba 4.14.1, samba 4.13.6, samba 4.12.13
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T17:37:23.017Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1949442"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.samba.org/samba/security/CVE-2021-20254.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210430-0001/"
          },
          {
            "name": "FEDORA-2021-1d0807008b",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/"
          },
          {
            "name": "FEDORA-2021-7026246ea9",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/"
          },
          {
            "name": "GLSA-202105-22",
            "tags": [
              "vendor-advisory",
              "x_refsource_GENTOO",
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/202105-22"
          },
          {
            "name": "[debian-lts-announce] 20210529 [SECURITY] [DLA 2668-1] samba security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "samba",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "samba 4.14.1, samba 4.13.6, samba 4.12.13"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-05-29T12:06:12.000Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1949442"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.samba.org/samba/security/CVE-2021-20254.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210430-0001/"
        },
        {
          "name": "FEDORA-2021-1d0807008b",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/"
        },
        {
          "name": "FEDORA-2021-7026246ea9",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/"
        },
        {
          "name": "GLSA-202105-22",
          "tags": [
            "vendor-advisory",
            "x_refsource_GENTOO"
          ],
          "url": "https://security.gentoo.org/glsa/202105-22"
        },
        {
          "name": "[debian-lts-announce] 20210529 [SECURITY] [DLA 2668-1] samba security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "secalert@redhat.com",
          "ID": "CVE-2021-20254",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "samba",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "samba 4.14.1, samba 4.13.6, samba 4.12.13"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-125"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://bugzilla.redhat.com/show_bug.cgi?id=1949442",
              "refsource": "MISC",
              "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1949442"
            },
            {
              "name": "https://www.samba.org/samba/security/CVE-2021-20254.html",
              "refsource": "MISC",
              "url": "https://www.samba.org/samba/security/CVE-2021-20254.html"
            },
            {
              "name": "https://security.netapp.com/advisory/ntap-20210430-0001/",
              "refsource": "MISC",
              "url": "https://security.netapp.com/advisory/ntap-20210430-0001/"
            },
            {
              "name": "FEDORA-2021-1d0807008b",
              "refsource": "FEDORA",
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/"
            },
            {
              "name": "FEDORA-2021-7026246ea9",
              "refsource": "FEDORA",
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/"
            },
            {
              "name": "GLSA-202105-22",
              "refsource": "GENTOO",
              "url": "https://security.gentoo.org/glsa/202105-22"
            },
            {
              "name": "[debian-lts-announce] 20210529 [SECURITY] [DLA 2668-1] samba security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2021-20254",
    "datePublished": "2021-05-05T13:36:32.000Z",
    "dateReserved": "2020-12-17T00:00:00.000Z",
    "dateUpdated": "2024-08-03T17:37:23.017Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-20254",
      "date": "2026-06-05",
      "epss": "0.01764",
      "percentile": "0.82993"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-20254\",\"sourceIdentifier\":\"secalert@redhat.com\",\"published\":\"2021-05-05T14:15:07.883\",\"lastModified\":\"2024-11-21T05:46:13.203\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity.\"},{\"lang\":\"es\",\"value\":\"Se encontr\u00f3 un fallo en samba.\u0026#xa0;El servidor de archivos smbd de Samba debe asignar Windows group identities (SIDs) a unix group ids (gids).\u0026#xa0;El c\u00f3digo que lleva a cabo esto ten\u00eda un fallo que podr\u00eda permitirle leer datos m\u00e1s all\u00e1 del final de la matriz en el caso de que se hubiera agregado una entrada de cach\u00e9 negativa a la cach\u00e9 de mapeo.\u0026#xa0;Esto podr\u00eda causar que el c\u00f3digo de llamada devuelva esos valores al token de proceso que almacena la pertenencia al grupo de un usuario.\u0026#xa0;La mayor amenaza de esta vulnerabilidad es la confidencialidad e integridad de los datos\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N\",\"baseScore\":6.8,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.6,\"impactScore\":5.2}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:M/Au:S/C:P/I:P/A:N\",\"baseScore\":4.9,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"MEDIUM\",\"authentication\":\"SINGLE\",\"confidentialityImpact\":\"PARTIAL\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"NONE\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":6.8,\"impactScore\":4.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"3.6.0\",\"versionEndExcluding\":\"4.12.15\",\"matchCriteriaId\":\"B84DE447-47C2-4AFB-867C-20D372058366\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"4.13.0\",\"versionEndExcluding\":\"4.13.8\",\"matchCriteriaId\":\"1B8AF688-C755-4E0A-A80E-D74BF89678D6\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"4.14.0\",\"versionEndExcluding\":\"4.14.4\",\"matchCriteriaId\":\"145DC5A1-4F1B-41BC-8B13-CB270B960BA0\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"36D96259-24BD-44E2-96D9-78CE1D41F956\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"E460AA51-FCDA-46B9-AE97-E6676AA5E194\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"142AD0DD-4CF3-4D74-9442-459CE3347E3A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"F4CFF558-3C47-480D-A2F0-BABF26042943\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"DEECE5FC-CACF-4496-A3E7-164736409252\"}]}]}],\"references\":[{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=1949442\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Issue Tracking\",\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://security.gentoo.org/glsa/202105-22\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://security.netapp.com/advisory/ntap-20210430-0001/\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.samba.org/samba/security/CVE-2021-20254.html\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=1949442\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://security.gentoo.org/glsa/202105-22\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://security.netapp.com/advisory/ntap-20210430-0001/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.samba.org/samba/security/CVE-2021-20254.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.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.