CVE-2018-21029
highpriority · track · 40EPSS 0.031 · 88 %ileEUUSEPSS · scored 2026-10-28
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)
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (30)
External citations — patches, advisories, analysis.
- https://blog.cloudflare.com/dns-encryption-explained/cnnvd
- https://github.com/systemd/systemdPatchcnnvd
- https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207cnnvd
- https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207cnnvd
- https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63cnnvd
- https://github.com/systemd/systemd/issues/9397cnnvd
- https://github.com/systemd/systemd/pull/13870cnnvd
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/cnnvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan