{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2016-1551",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2016-1551",
    "idYear": 2016,
    "status": "PUBLISHED",
    "publishedAt": "2017-01-27T17:00:00.000Z",
    "updatedAt": "2024-08-05T23:02:12.002Z",
    "importedAt": "2026-10-24T01:55:48.151Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": null,
      "summary": "ntpd in NTP 4.2.8p3 and NTPsec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 relies on the underlying operating system to protect it from requests that impersonate reference clocks. Because reference clocks are treated like other peers and stored in the same structure, any packet with a source ip address of a reference clock (127.127.1.1 for example) that reaches the receive() function will match that reference clock's peer record and will be treated as a trusted peer. Any system that lacks the typical martian packet filtering which would block these packets is in danger of having its time controlled by an attacker.",
      "affected": [
        {
          "vendor": "NTP Project",
          "product": "NTP",
          "versions": [
            {
              "version": "4.2.8p3",
              "status": "affected"
            },
            {
              "version": "4.2.8p4",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "NTPsec Project",
          "product": "NTPSec",
          "versions": [
            {
              "version": "3e160db8dc248a0bcb053b56a80167dc742d2b74",
              "status": "affected"
            },
            {
              "version": "a5fb34b9cc89b92a8fef2f459004865c93bb7f92",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}