{"id":"CVE-2015-1853","url":"https://www.cyber-defence.io/tools/cve/CVE-2015-1853","generatedAt":"2026-10-27T22:06:05.005Z","title":"chrony before 1.31.1 does not properly protect state variables in authenticated symmetric NTP associations, which allows remote attackers with knowledge of NTP peering to cause a denial of service (inability to synchronize) via random timestamps in…","description":"chrony before 1.31.1 does not properly protect state variables in authenticated symmetric NTP associations, which allows remote attackers with knowledge of NTP peering to cause a denial of service (inability to synchronize) via random timestamps in crafted NTP data packets.","published":"2019-12-09T19:15:14.000Z","lastModified":"2026-06-17T00:23:07.000Z","status":"Modified","sourceIdentifier":"secalert@redhat.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["tuxfamily/chrony"],"epss":{"score":0.01696,"percentile":0.76987,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.70%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://chrony.tuxfamily.org/News.html","tags":["Release Notes","Vendor Advisory"],"source":"secalert@redhat.com"},{"url":"https://security.gentoo.org/glsa/201507-01","tags":["Third Party Advisory"],"source":"secalert@redhat.com"},{"url":"http://chrony.tuxfamily.org/News.html","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/201507-01","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2015-1853","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}