{"id":"CVE-2020-8616","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-8616","generatedAt":"2026-11-05T02:12:45.840Z","title":"A malicious actor who intentionally exploits this lack of effective limitation on the number of fetches performed when processing referrals can, through the use of specially crafted referrals, cause a recursing server to issue a very large number of…","description":"A malicious actor who intentionally exploits this lack of effective limitation on the number of fetches performed when processing referrals can, through the use of specially crafted referrals, cause a recursing server to issue a very large number of fetches in an attempt to process the referral. This has at least two potential effects: The performance of the recursing server can potentially be degraded by the additional work required to perform these fetches, and The attacker can exploit this behavior to use the recursing server as a reflector in a reflection attack with a high amplification factor.","published":"2020-05-19T14:15:12.000Z","lastModified":"2026-06-17T03:26:39.000Z","status":"Modified","sourceIdentifier":"security-officer@isc.org","cvss":{"version":"3.1","score":8.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H"},"cwe":["CWE-400"],"affected":["isc/bind","debian/debian linux"],"epss":{"score":0.1088,"percentile":0.95869,"date":"2026-11-03","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 10.9%, higher than 96% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html","source":"security-officer@isc.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html","source":"security-officer@isc.org"},{"url":"http://www.nxnsattack.com","tags":["Exploit","Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"http://www.openwall.com/lists/oss-security/2020/05/19/4","tags":["Mailing List","Patch","Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"https://kb.isc.org/docs/cve-2020-8616","tags":["Patch","Vendor Advisory"],"source":"security-officer@isc.org"},{"url":"https://lists.debian.org/debian-lts-announce/2020/05/msg00031.html","source":"security-officer@isc.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKJXVBOKZ36ER3EUCR7VRB7WGHIIMPNJ/","source":"security-officer@isc.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WOGCJS2XQ3SQNF4W6GLZ73LWZJ6ZZWZI/","source":"security-officer@isc.org"},{"url":"https://security.netapp.com/advisory/ntap-20200522-0002/","source":"security-officer@isc.org"},{"url":"https://usn.ubuntu.com/4365-1/","source":"security-officer@isc.org"},{"url":"https://usn.ubuntu.com/4365-2/","source":"security-officer@isc.org"},{"url":"https://www.debian.org/security/2020/dsa-4689","tags":["Third Party Advisory"],"source":"security-officer@isc.org"},{"url":"https://www.synology.com/security/advisory/Synology_SA_20_12","source":"security-officer@isc.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00041.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00044.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.nxnsattack.com","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2020/05/19/4","tags":["Mailing List","Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://kb.isc.org/docs/cve-2020-8616","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2020/05/msg00031.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JKJXVBOKZ36ER3EUCR7VRB7WGHIIMPNJ/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WOGCJS2XQ3SQNF4W6GLZ73LWZJ6ZZWZI/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20200522-0002/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4365-1/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4365-2/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2020/dsa-4689","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.synology.com/security/advisory/Synology_SA_20_12","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-8616","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."}