CVE-2018-21029
CRITICALsystemd 239-245 - Improper Certificate Validation in DNS Over TLS
Title source: llmDescription
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)
References (9)
Core 9
Core References
Issue Tracking, Third Party Advisory x_refsource_misc
https://github.com/systemd/systemd/issues/9397
Third Party Advisory x_refsource_misc
https://blog.cloudflare.com/dns-encryption-explained/
Patch, Third Party Advisory x_refsource_misc
https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/
Third Party Advisory x_refsource_confirm
https://security.netapp.com/advisory/ntap-20191122-0002/
Patch, Third Party Advisory x_refsource_misc
https://github.com/systemd/systemd/pull/13870
Exploit, Third Party Advisory x_refsource_misc
https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207
Exploit, Third Party Advisory x_refsource_misc
https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207
Third Party Advisory x_refsource_misc
https://tools.ietf.org/html/rfc7858#section-4.1
Scores
CVSS v3
9.8
EPSS
0.0314
EPSS Percentile
86.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-295
Status
published
Products (2)
fedoraproject/fedora
31
systemd_project/systemd
239 - 244
Published
Oct 30, 2019
Tracked Since
Feb 18, 2026