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FKIE_CVE-2021-3448

Vulnerability from fkie_nvd - Published: 2021-04-08 23:15 - Updated: 2026-06-17 04:05
Severity
4.0 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
4.0 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
Summary
A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity.
References
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1939368Exploit, Issue Tracking, Patch, Third Party Advisory
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CVTJUOFFFHINLKWAOC2ZSC5MOPD4SJ24/
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHG7GWSQWKF7JXIMLOGJBKZWBB4VIAJ7/
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/
secalert@redhat.comhttps://security.gentoo.org/glsa/202105-20Third Party Advisory
secalert@redhat.comhttps://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://bugzilla.redhat.com/show_bug.cgi?id=1939368Exploit, Issue Tracking, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CVTJUOFFFHINLKWAOC2ZSC5MOPD4SJ24/
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHG7GWSQWKF7JXIMLOGJBKZWBB4VIAJ7/
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202105-20Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
Impacted products
Vendor Product Version
thekelleys dnsmasq *
redhat enterprise_linux 8.0
fedoraproject fedora 32
fedoraproject fedora 33
fedoraproject fedora 34
oracle communications_cloud_native_core_network_function_cloud_native_environment 1.9.0
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "dnsmasq",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "dnsmasq 2.85"
            }
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      ],
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity."
    },
    {
      "lang": "es",
      "value": "Se encontr\u00f3 un fallo en dnsmasq en versiones anteriores a 2.85.\u0026#xa0;Cuando es configurado para usar un servidor espec\u00edfico para una interfaz de red determinada, dnsmasq usa un puerto fijado para enviar consultas.\u0026#xa0;Un atacante en la red, capaz de encontrar el puerto de salida usado por dnsmasq, solo necesita adivinar la ID de transmisi\u00f3n aleatoria para falsificar una respuesta y lograr que dnsmasq la acepte.\u0026#xa0;Este fallo hace que un ataque de envenenamiento de cach\u00e9 de DNS sea mucho m\u00e1s f\u00e1cil.\u0026#xa0;La mayor amenaza de esta vulnerabilidad es la integridad de los datos"
    }
  ],
  "id": "CVE-2021-3448",
  "lastModified": "2026-06-17T04:05:07.153",
  "metrics": {
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        "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,
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          "role": "CISA Coordinator",
          "timestamp": "2025-12-03T00:40:29.580724Z",
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  "published": "2021-04-08T23:15:12.597",
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}



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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.