FKIE_CVE-2025-24356

Vulnerability from fkie_nvd - Published: 2025-01-27 18:15 - Updated: 2026-06-17 08:58
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
fastd is a VPN daemon which tunnels IP packets and Ethernet frames over UDP. When receiving a data packet from an unknown IP address/port combination, fastd will assume that one of its connected peers has moved to a new address and initiate a reconnect by sending a handshake packet. This "fast reconnect" avoids having to wait for a session timeout (up to ~90s) until a new connection is established. Even a 1-byte UDP packet just containing the fastd packet type header can trigger a much larger handshake packet (~150 bytes of UDP payload). Including IPv4 and UDP headers, the resulting amplification factor is roughly 12-13. By sending data packets with a spoofed source address to fastd instances reachable on the internet, this amplification of UDP traffic might be used to facilitate a Distributed Denial of Service attack. This vulnerability is fixed in v23.
References
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/1f233bee76b722c0b3f9024f2c39c72e9f7e5843Patch
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/3940150e801d0c91460491bec32cbcc5bbc89d5fPatch
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/5f63fcfc18ae9cad023fa463b152d5e14192b5a8Patch
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/9df7e516378441d2d17b89f9db5c27c8312d8f12Patch
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/c1a07b3f2b9066c3713c68547da700b85d60f4f7Patch
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/ce1b79b12dbfa796743b5f3a50789ade965b7023Patch
security-advisories@github.comhttps://github.com/neocturne/fastd/commit/d03a0a17347efb5293e42fde7d982781e90f14efPatch
security-advisories@github.comhttps://github.com/neocturne/fastd/security/advisories/GHSA-pggg-vpfv-4rcvMitigation, Patch, Vendor Advisory
Impacted products
Vendor Product Version
fastd_project fastd *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "fastd",
          "vendor": "neocturne",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 23"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:fastd_project:fastd:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "13F48C42-FD6C-4BB0-ACB5-56235C3E04B1",
              "versionEndExcluding": "23.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "fastd is a VPN daemon which tunnels IP packets and Ethernet frames over UDP. When receiving a data packet from an unknown IP address/port combination, fastd will assume that one of its connected peers has moved to a new address and initiate a reconnect by sending a handshake packet. This \"fast reconnect\" avoids having to wait for a session timeout (up to ~90s) until a new connection is established. Even a 1-byte UDP packet just containing the fastd packet type header can trigger a much larger handshake packet (~150 bytes of UDP payload). Including IPv4 and UDP headers, the resulting amplification factor is roughly 12-13. By sending data packets with a spoofed source address to fastd instances reachable on the internet, this amplification of UDP traffic might be used to facilitate a Distributed Denial of Service attack. This vulnerability is fixed in v23."
    },
    {
      "lang": "es",
      "value": "fastd es una VPN daemon que tuneliza paquetes IP y tramas Ethernet sobre UDP. Al recibir un paquete de datos de una combinaci\u00f3n desconocida de direcci\u00f3n IP/puerto, fastd asumir\u00e1 que uno de sus pares conectados se ha mudado a una nueva direcci\u00f3n e iniciar\u00e1 una reconexi\u00f3n enviando un paquete handshake. Esta \"reconexi\u00f3n r\u00e1pida\" evita tener que esperar a que se agote el tiempo de espera de la sesi\u00f3n (hasta ~90 s) hasta que se establezca una nueva conexi\u00f3n. Incluso un paquete UDP de 1 byte que solo contenga el encabezado de tipo de paquete fastd puede activar un paquete handshakee mucho m\u00e1s grande (~150 bytes de UDP payload). incluida IPv4 y encabezados UDP, el factor de amplificaci\u00f3n resultante es aproximadamente 12-13. Al enviar paquetes de datos con una direcci\u00f3n de origen falsificada a instancias de fastd accesibles en Internet, esta amplificaci\u00f3n del tr\u00e1fico UDP podr\u00eda usarse para facilitar un ataque de denegaci\u00f3n de servicio distribuido. Esta vulnerabilidad se corrigi\u00f3 en la v23."
    }
  ],
  "id": "CVE-2025-24356",
  "lastModified": "2026-06-17T08:58:37.750",
  "metrics": {
    "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"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-24356",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-01-28T15:38:54.975943Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-01-27T18:15:41.347",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/1f233bee76b722c0b3f9024f2c39c72e9f7e5843"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/3940150e801d0c91460491bec32cbcc5bbc89d5f"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/5f63fcfc18ae9cad023fa463b152d5e14192b5a8"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/9df7e516378441d2d17b89f9db5c27c8312d8f12"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/c1a07b3f2b9066c3713c68547da700b85d60f4f7"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/ce1b79b12dbfa796743b5f3a50789ade965b7023"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/neocturne/fastd/commit/d03a0a17347efb5293e42fde7d982781e90f14ef"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Mitigation",
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/neocturne/fastd/security/advisories/GHSA-pggg-vpfv-4rcv"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-405"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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