{"id":"CVE-2018-21029","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-21029","generatedAt":"2026-10-28T23:38:41.900Z","title":"NOTE: This has been disputed by the developer as not a vulnerability since hostname validation does not have anything to do with this issue (i.e. there is no hostname to be sent)","description":"systemd 239 through 245 accepts any certificate signed by a trusted certificate authority for DNS Over TLS. Server Name Indication (SNI) is not sent, and there is no hostname validation with the GnuTLS backend. NOTE: This has been disputed by the developer as not a vulnerability since hostname validation does not have anything to do with this issue (i.e. there is no hostname to be sent)","published":"2019-10-30T22:15:11.000Z","lastModified":"2026-06-17T01:53:59.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-295"],"affected":["systemd project/systemd","fedoraproject/fedora"],"epss":{"score":0.03138,"percentile":0.87834,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (3.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://blog.cloudflare.com/dns-encryption-explained/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/systemd/systemd/issues/9397","tags":["Issue Tracking","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/systemd/systemd/pull/13870","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/","source":"cve@mitre.org"},{"url":"https://security.netapp.com/advisory/ntap-20191122-0002/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://tools.ietf.org/html/rfc7858#section-4.1","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://blog.cloudflare.com/dns-encryption-explained/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/systemd/systemd/issues/9397","tags":["Issue Tracking","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/systemd/systemd/pull/13870","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20191122-0002/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://tools.ietf.org/html/rfc7858#section-4.1","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-21029","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."}