{"api_version":"1","generated_at":"2026-07-12T21:19:39+00:00","cve":"CVE-2016-1551","urls":{"html":"https://cve.report/CVE-2016-1551","api":"https://cve.report/api/cve/CVE-2016-1551.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2016-1551","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2016-1551"},"summary":{"title":"CVE-2016-1551","description":"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.","state":"PUBLISHED","assigner":"certcc","published_at":"2017-01-27 17:59:00","updated_at":"2025-04-20 01:37:25"},"problem_types":["CWE-254","unspecified"],"metrics":[{"version":"3.0","source":"nvd@nist.gov","type":"Primary","score":"3.7","severity":"LOW","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","data":{"version":"3.0","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","baseScore":3.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"}},{"version":"2.0","source":"nvd@nist.gov","type":"Primary","score":"2.6","severity":"","vector":"AV:N/AC:H/Au:N/C:N/I:P/A:N","data":{"version":"2.0","vectorString":"AV:N/AC:H/Au:N/C:N/I:P/A:N","baseScore":2.6,"accessVector":"NETWORK","accessComplexity":"HIGH","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"NONE"}}],"references":[{"url":"http://www.talosintelligence.com/reports/TALOS-2016-0132/","name":"http://www.talosintelligence.com/reports/TALOS-2016-0132/","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"],"title":"Cisco Talos - Talos 2016 0132","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://security.netapp.com/advisory/ntap-20171004-0002/","name":"https://security.netapp.com/advisory/ntap-20171004-0002/","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":[],"title":"April 2016 Network Time Protocol Daemon (ntpd) Vulnerabilities in Multiple NetApp Products | NetApp Product Security","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc","name":"https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":[],"title":"","mime":"text/plain","httpstatus":"200","archivestatus":"200"},{"url":"https://security.gentoo.org/glsa/201607-15","name":"https://security.gentoo.org/glsa/201607-15","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":[],"title":"NTP: Multiple vulnerabilities (GLSA 201607-15) — Gentoo Security","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"http://www.securitytracker.com/id/1035705","name":"http://www.securitytracker.com/id/1035705","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":[],"title":"ntp Multiple Bugs Let Remote Users Spoof Messages, Obtain Potentially Sensitive Information, Modify Time, and Deny Service - SecurityTracker","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"http://www.securityfocus.com/bid/88219","name":"http://www.securityfocus.com/bid/88219","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory","VDB Entry"],"title":"NTP CVE-2016-1551 Remote Security Vulnerability","mime":"text/html","httpstatus":"200","archivestatus":"0"},{"url":"http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html","name":"http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"],"title":"Oracle Solaris Bulletin - April 2016","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.cve.org/CVERecord?id=CVE-2016-1551","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2016-1551","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"NTP Project","product":"NTP","version":"affected 4.2.8p3","platforms":[]},{"source":"CNA","vendor":"NTP Project","product":"NTP","version":"affected 4.2.8p4","platforms":[]},{"source":"CNA","vendor":"NTPsec Project","product":"NTPSec","version":"affected 3e160db8dc248a0bcb053b56a80167dc742d2b74","platforms":[]},{"source":"CNA","vendor":"NTPsec Project","product":"NTPSec","version":"affected a5fb34b9cc89b92a8fef2f459004865c93bb7f92","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2016","cve_id":"1551","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"ntp","cpe5":"ntp","cpe6":"4.2.8","cpe7":"p3","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2016","cve_id":"1551","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"ntpsec","cpe5":"ntpsec","cpe6":"a5fb34b9cc89b92a8fef2f459004865c93bb7f92","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2024-08-05T23:02:12.002Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"name":"88219","tags":["vdb-entry","x_refsource_BID","x_transferred"],"url":"http://www.securityfocus.com/bid/88219"},{"tags":["x_refsource_MISC","x_transferred"],"url":"http://www.talosintelligence.com/reports/TALOS-2016-0132/"},{"name":"1035705","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred"],"url":"http://www.securitytracker.com/id/1035705"},{"tags":["x_refsource_CONFIRM","x_transferred"],"url":"http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html"},{"tags":["x_refsource_CONFIRM","x_transferred"],"url":"https://security.netapp.com/advisory/ntap-20171004-0002/"},{"name":"FreeBSD-SA-16:16","tags":["vendor-advisory","x_refsource_FREEBSD","x_transferred"],"url":"https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc"},{"name":"GLSA-201607-15","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred"],"url":"https://security.gentoo.org/glsa/201607-15"}],"title":"CVE Program Container"}],"cna":{"affected":[{"product":"NTP","vendor":"NTP Project","versions":[{"status":"affected","version":"4.2.8p3"},{"status":"affected","version":"4.2.8p4"}]},{"product":"NTPSec","vendor":"NTPsec Project","versions":[{"status":"affected","version":"3e160db8dc248a0bcb053b56a80167dc742d2b74"},{"status":"affected","version":"a5fb34b9cc89b92a8fef2f459004865c93bb7f92"}]}],"datePublic":"2016-04-26T00:00:00.000Z","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"description":"unspecified","lang":"en","type":"text"}]}],"providerMetadata":{"dateUpdated":"2017-11-20T15:57:01.000Z","orgId":"37e5125f-f79b-445b-8fad-9564f167944b","shortName":"certcc"},"references":[{"name":"88219","tags":["vdb-entry","x_refsource_BID"],"url":"http://www.securityfocus.com/bid/88219"},{"tags":["x_refsource_MISC"],"url":"http://www.talosintelligence.com/reports/TALOS-2016-0132/"},{"name":"1035705","tags":["vdb-entry","x_refsource_SECTRACK"],"url":"http://www.securitytracker.com/id/1035705"},{"tags":["x_refsource_CONFIRM"],"url":"http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html"},{"tags":["x_refsource_CONFIRM"],"url":"https://security.netapp.com/advisory/ntap-20171004-0002/"},{"name":"FreeBSD-SA-16:16","tags":["vendor-advisory","x_refsource_FREEBSD"],"url":"https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc"},{"name":"GLSA-201607-15","tags":["vendor-advisory","x_refsource_GENTOO"],"url":"https://security.gentoo.org/glsa/201607-15"}],"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"cert@cert.org","ID":"CVE-2016-1551","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"NTP","version":{"version_data":[{"version_value":"4.2.8p3"},{"version_value":"4.2.8p4"}]}}]},"vendor_name":"NTP Project"},{"product":{"product_data":[{"product_name":"NTPSec","version":{"version_data":[{"version_value":"3e160db8dc248a0bcb053b56a80167dc742d2b74"},{"version_value":"a5fb34b9cc89b92a8fef2f459004865c93bb7f92"}]}}]},"vendor_name":"NTPsec Project"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"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."}]},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"unspecified"}]}]},"references":{"reference_data":[{"name":"88219","refsource":"BID","url":"http://www.securityfocus.com/bid/88219"},{"name":"http://www.talosintelligence.com/reports/TALOS-2016-0132/","refsource":"MISC","url":"http://www.talosintelligence.com/reports/TALOS-2016-0132/"},{"name":"1035705","refsource":"SECTRACK","url":"http://www.securitytracker.com/id/1035705"},{"name":"http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html","refsource":"CONFIRM","url":"http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html"},{"name":"https://security.netapp.com/advisory/ntap-20171004-0002/","refsource":"CONFIRM","url":"https://security.netapp.com/advisory/ntap-20171004-0002/"},{"name":"FreeBSD-SA-16:16","refsource":"FREEBSD","url":"https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc"},{"name":"GLSA-201607-15","refsource":"GENTOO","url":"https://security.gentoo.org/glsa/201607-15"}]}}}},"cveMetadata":{"assignerOrgId":"37e5125f-f79b-445b-8fad-9564f167944b","assignerShortName":"certcc","cveId":"CVE-2016-1551","datePublished":"2017-01-27T17:00:00.000Z","dateReserved":"2016-01-07T00:00:00.000Z","dateUpdated":"2024-08-05T23:02:12.002Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.1"},"nvd":{"publishedDate":"2017-01-27 17:59:00","lastModifiedDate":"2025-04-20 01:37:25","problem_types":["CWE-254","unspecified"],"metrics":{"cvssMetricV30":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.0","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N","baseScore":3.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":2.2,"impactScore":1.4}],"cvssMetricV2":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"2.0","vectorString":"AV:N/AC:H/Au:N/C:N/I:P/A:N","baseScore":2.6,"accessVector":"NETWORK","accessComplexity":"HIGH","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"NONE"},"baseSeverity":"LOW","exploitabilityScore":4.9,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:ntp:ntp:4.2.8:p3:*:*:*:*:*:*","matchCriteriaId":"41E44E9F-6383-4E12-AEDC-B653FEA77A48"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:ntpsec:ntpsec:a5fb34b9cc89b92a8fef2f459004865c93bb7f92:*:*:*:*:*:*:*","matchCriteriaId":"5765FE6F-2E10-4712-8FD7-EA982572FB17"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2016","CveId":"1551","Ordinal":"1","Title":"CVE-2016-1551","CVE":"CVE-2016-1551","Year":"2016"},"notes":[{"CveYear":"2016","CveId":"1551","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"CVE-2016-1551"},{"CveYear":"2016","CveId":"1551","Ordinal":"2","NoteData":"2017-01-27","Type":"Other","Title":"Published"},{"CveYear":"2016","CveId":"1551","Ordinal":"3","NoteData":"2017-11-20","Type":"Other","Title":"Modified"}]}}}