GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2020-14303 (GCVE-0-2020-14303)

Vulnerability from cvelistv5 – Published: 2020-07-06 17:12 – Updated: 2024-08-04 12:39
VLAI
Summary
A flaw was found in the AD DC NBT server in all Samba versions before 4.10.17, before 4.11.11 and before 4.12.4. A samba user could send an empty UDP packet to cause the samba server to crash.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • Uncontrolled Resource Consumption
Assigner
References
Impacted products
Vendor Product Version CPE status
n/a Samba Affected: All Samba versions before 4.10.17, before 4.11.11 and before 4.12.4
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T12:39:36.168Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1851298%3B"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.samba.org/samba/security/CVE-2020-14303.html"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20200709-0003/"
          },
          {
            "name": "FEDORA-2020-5131d30947",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6YLNQ5GRXUKYRUAOFZ4DUBVN4SMTL6Q2/"
          },
          {
            "name": "openSUSE-SU-2020:0984",
            "tags": [
              "vendor-advisory",
              "x_refsource_SUSE",
              "x_transferred"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00030.html"
          },
          {
            "name": "openSUSE-SU-2020:1023",
            "tags": [
              "vendor-advisory",
              "x_refsource_SUSE",
              "x_transferred"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00054.html"
          },
          {
            "name": "GLSA-202007-15",
            "tags": [
              "vendor-advisory",
              "x_refsource_GENTOO",
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/202007-15"
          },
          {
            "name": "USN-4454-2",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4454-2/"
          },
          {
            "name": "USN-4454-1",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4454-1/"
          },
          {
            "name": "openSUSE-SU-2020:1313",
            "tags": [
              "vendor-advisory",
              "x_refsource_SUSE",
              "x_transferred"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00002.html"
          },
          {
            "name": "[debian-lts-announce] 20201123 [SECURITY] [DLA 2463-1] samba security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Samba",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "All Samba versions before 4.10.17, before 4.11.11 and before 4.12.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in the AD DC NBT server in all Samba versions before 4.10.17, before 4.11.11 and before 4.12.4. A samba user could send an empty UDP packet to cause the samba server to crash."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2020-11-23T04:06:20.000Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1851298%3B"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.samba.org/samba/security/CVE-2020-14303.html"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20200709-0003/"
        },
        {
          "name": "FEDORA-2020-5131d30947",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6YLNQ5GRXUKYRUAOFZ4DUBVN4SMTL6Q2/"
        },
        {
          "name": "openSUSE-SU-2020:0984",
          "tags": [
            "vendor-advisory",
            "x_refsource_SUSE"
          ],
          "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00030.html"
        },
        {
          "name": "openSUSE-SU-2020:1023",
          "tags": [
            "vendor-advisory",
            "x_refsource_SUSE"
          ],
          "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00054.html"
        },
        {
          "name": "GLSA-202007-15",
          "tags": [
            "vendor-advisory",
            "x_refsource_GENTOO"
          ],
          "url": "https://security.gentoo.org/glsa/202007-15"
        },
        {
          "name": "USN-4454-2",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4454-2/"
        },
        {
          "name": "USN-4454-1",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4454-1/"
        },
        {
          "name": "openSUSE-SU-2020:1313",
          "tags": [
            "vendor-advisory",
            "x_refsource_SUSE"
          ],
          "url": "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00002.html"
        },
        {
          "name": "[debian-lts-announce] 20201123 [SECURITY] [DLA 2463-1] samba security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "secalert@redhat.com",
          "ID": "CVE-2020-14303",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "Samba",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "All Samba versions before 4.10.17, before 4.11.11 and before 4.12.4"
                          }
                        ]
                      }
                    }
                  ]
                },
                "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 the AD DC NBT server in all Samba versions before 4.10.17, before 4.11.11 and before 4.12.4. A samba user could send an empty UDP packet to cause the samba server to crash."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "Uncontrolled Resource Consumption"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://bugzilla.redhat.com/show_bug.cgi?id=1851298;",
              "refsource": "MISC",
              "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1851298;"
            },
            {
              "name": "https://www.samba.org/samba/security/CVE-2020-14303.html",
              "refsource": "MISC",
              "url": "https://www.samba.org/samba/security/CVE-2020-14303.html"
            },
            {
              "name": "https://security.netapp.com/advisory/ntap-20200709-0003/",
              "refsource": "CONFIRM",
              "url": "https://security.netapp.com/advisory/ntap-20200709-0003/"
            },
            {
              "name": "FEDORA-2020-5131d30947",
              "refsource": "FEDORA",
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6YLNQ5GRXUKYRUAOFZ4DUBVN4SMTL6Q2/"
            },
            {
              "name": "openSUSE-SU-2020:0984",
              "refsource": "SUSE",
              "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00030.html"
            },
            {
              "name": "openSUSE-SU-2020:1023",
              "refsource": "SUSE",
              "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00054.html"
            },
            {
              "name": "GLSA-202007-15",
              "refsource": "GENTOO",
              "url": "https://security.gentoo.org/glsa/202007-15"
            },
            {
              "name": "USN-4454-2",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4454-2/"
            },
            {
              "name": "USN-4454-1",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4454-1/"
            },
            {
              "name": "openSUSE-SU-2020:1313",
              "refsource": "SUSE",
              "url": "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00002.html"
            },
            {
              "name": "[debian-lts-announce] 20201123 [SECURITY] [DLA 2463-1] samba security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2020-14303",
    "datePublished": "2020-07-06T17:12:08.000Z",
    "dateReserved": "2020-06-17T00:00:00.000Z",
    "dateUpdated": "2024-08-04T12:39:36.168Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2020-14303",
      "date": "2026-09-18",
      "epss": "0.03539",
      "percentile": "0.88734"
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "F2F67C7B-A323-4396-8CA1-0F81CA18E3B4",
                    "versionEndExcluding": "4.10.17",
                    "versionStartIncluding": "4.10.0",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "EE656EC4-DE4C-4921-A22D-88C9CEDFFECB",
                    "versionEndExcluding": "4.11.11",
                    "versionStartIncluding": "4.11.0",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "6D8FF3AF-B703-4021-8156-3D767FA10B8E",
                    "versionEndExcluding": "4.12.4",
                    "versionStartIncluding": "4.12.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*",
                    "matchCriteriaId": "80F0FA5D-8D3B-4C0E-81E2-87998286AF33",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*",
                    "matchCriteriaId": "B620311B-34A3-48A6-82DF-6F078D7A4493",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*",
                    "matchCriteriaId": "B009C22E-30A4-4288-BCF6-C3E81DEAF45A",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*",
                    "matchCriteriaId": "CB66DB75-2B16-4EBF-9B93-CE49D8086E41",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*",
                    "matchCriteriaId": "815D70A8-47D3-459C-A32C-9FEACA0659D1",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*",
                    "matchCriteriaId": "7A5301BF-1402-4BE0-A0F8-69FBE79BC6D6",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "902B8056-9E37-443B-8905-8AA93E2447FB",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "A flaw was found in the AD DC NBT server in all Samba versions before 4.10.17, before 4.11.11 and before 4.12.4. A samba user could send an empty UDP packet to cause the samba server to crash."
          },
          {
            "lang": "es",
            "value": "Se encontr\u00f3 un fallo en el servidor AD DC NBT en todas las versiones de Samba anteriores a 4.10.17, anteriores a 4.11.11 y anteriores a 4.12.4. Un usuario de samba podr\u00eda enviar un paquete UDP vac\u00edo para hacer que el servidor de samba se bloquee"
          }
        ],
        "id": "CVE-2020-14303",
        "lastModified": "2024-11-21T05:02:57.837",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "MEDIUM",
              "cvssData": {
                "accessComplexity": "LOW",
                "accessVector": "NETWORK",
                "authentication": "NONE",
                "availabilityImpact": "PARTIAL",
                "baseScore": 5.0,
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
                "version": "2.0"
              },
              "exploitabilityScore": 10.0,
              "impactScore": 2.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2020-07-06T18:15:20.323",
        "references": [
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00030.html"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00054.html"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00002.html"
          },
          {
            "source": "secalert@redhat.com",
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1851298%3B"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html"
          },
          {
            "source": "secalert@redhat.com",
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6YLNQ5GRXUKYRUAOFZ4DUBVN4SMTL6Q2/"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.gentoo.org/glsa/202007-15"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20200709-0003/"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4454-1/"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4454-2/"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.samba.org/samba/security/CVE-2020-14303.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00030.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00054.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00002.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1851298%3B"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6YLNQ5GRXUKYRUAOFZ4DUBVN4SMTL6Q2/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.gentoo.org/glsa/202007-15"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20200709-0003/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4454-1/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4454-2/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.samba.org/samba/security/CVE-2020-14303.html"
          }
        ],
        "sourceIdentifier": "secalert@redhat.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-834"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-06-26T22:25:46+00:00",
      "cve": "CVE-2020-14303",
      "id": "CVE-2020-14303",
      "initial_release_date": "2020-07-02T00:00:00+00:00",
      "product_status:known_not_affected": "117",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "samba: Empty UDP packet DoS in Samba AD DC nbtd",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2020/cve-2020-14303.json",
      "version": "3"
    }
  }
}



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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.