FKIE_CVE-2020-25686

Vulnerability from fkie_nvd - Published: 2021-01-20 17:15 - Updated: 2026-06-17 03:07
Severity
3.7 (Low) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Summary
A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
References
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1890125Issue Tracking, Patch, Third Party Advisory
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
secalert@redhat.comhttps://security.gentoo.org/glsa/202101-17Third Party Advisory
secalert@redhat.comhttps://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61Third Party Advisory
secalert@redhat.comhttps://www.debian.org/security/2021/dsa-4844Third Party Advisory
secalert@redhat.comhttps://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.redhat.com/show_bug.cgi?id=1890125Issue Tracking, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202101-17Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.debian.org/security/2021/dsa-4844Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.kb.cert.org/vuls/id/434904
Impacted products
Vendor Product Version
thekelleys dnsmasq *
fedoraproject fedora 32
fedoraproject fedora 33
debian debian_linux 10.0
arista eos *
arista eos *
arista eos *
arista eos *
arista eos *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "dnsmasq",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "dnsmasq 2.83"
            }
          ]
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:thekelleys:dnsmasq:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F38115DF-0F5C-442D-83D4-1125AAB4E2B7",
              "versionEndExcluding": "2.83",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "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",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "2E5C0DA1-5E51-40F1-82FE-CF7E391C07E4",
              "versionEndExcluding": "4.21.14m",
              "versionStartIncluding": "4.21",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "206E795F-BFE9-4AB9-A35F-60AC911F38E4",
              "versionEndExcluding": "4.22.9m",
              "versionStartIncluding": "4.22",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6FA15712-F804-4060-99C0-7370D6111B83",
              "versionEndExcluding": "4.23.7m",
              "versionStartIncluding": "4.23",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "21A321F5-CB56-4258-BB30-6753EECB89DD",
              "versionEndExcluding": "4.24.5m",
              "versionStartIncluding": "4.24",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "9445AF76-6AE4-46A6-A470-979ADBB19EE2",
              "versionEndExcluding": "4.25.2f",
              "versionStartIncluding": "4.25",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the \"Birthday Attacks\" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity."
    },
    {
      "lang": "es",
      "value": "Se encontr\u00f3 un fallo en dnsmasq versiones anteriores a 2.83.\u0026#xa0;Al recibir una consulta, dnsmasq no comprueba si existe una petici\u00f3n pendiente existente para el mismo nombre y reenv\u00eda una nueva petici\u00f3n.\u0026#xa0;Por defecto, se puede enviar un m\u00e1ximo de 150 consultas pendientes a los servidores aguas arriba, por lo que puede haber como m\u00e1ximo 150 consultas para el mismo nombre.\u0026#xa0;Este fallo permite a un atacante fuera de ruta en la red reduzca sustancialmente el n\u00famero de intentos que tendr\u00eda que realizar para falsificar una respuesta y hacer que dnsmasq la acepte.\u0026#xa0;Este problema se menciona en la secci\u00f3n \"Birthday Attacks\" de RFC5452.\u0026#xa0;Si se encadenaba con CVE-2020-25684, se reduce la complejidad del ataque de un ataque con \u00e9xito.\u0026#xa0;La mayor amenaza de esta vulnerabilidad es la integridad de los datos"
    }
  ],
  "id": "CVE-2020-25686",
  "lastModified": "2026-06-17T03:07:07.680",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "MEDIUM",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "confidentialityImpact": "NONE",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 8.6,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-01-20T17:15:13.000",
  "references": [
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Issue Tracking",
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1890125"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/"
    },
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://security.gentoo.org/glsa/202101-17"
    },
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61"
    },
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.debian.org/security/2021/dsa-4844"
    },
    {
      "source": "secalert@redhat.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.jsof-tech.com/disclosures/dnspooq/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Issue Tracking",
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1890125"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://security.gentoo.org/glsa/202101-17"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.debian.org/security/2021/dsa-4844"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.jsof-tech.com/disclosures/dnspooq/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://www.kb.cert.org/vuls/id/434904"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-358"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Secondary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    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.