CVE-2018-21029

Impact

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)

Affected products

Weakness classification

References

• NVD record
• CVE.org record
• https://blog.cloudflare.com/dns-encryption-explained/
• https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207
• https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207
• https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63
• https://github.com/systemd/systemd/issues/9397
• https://github.com/systemd/systemd/pull/13870
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/
• https://security.netapp.com/advisory/ntap-20191122-0002/
• https://tools.ietf.org/html/rfc7858#section-4.1
• https://blog.cloudflare.com/dns-encryption-explained/
• https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207
• https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207
• https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63
• https://github.com/systemd/systemd/issues/9397
• https://github.com/systemd/systemd/pull/13870
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/
• https://security.netapp.com/advisory/ntap-20191122-0002/
• https://tools.ietf.org/html/rfc7858#section-4.1