CVE-2018-21029

Public Exploit

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)

Category

9.8
CVSS
Severity: Critical
CVSS 3.1 •
CVSS 2.0 •
EPSS 1.56% Top 20%
Vendor Advisory fedoraproject.org
Affected: n/a n/a
Published at:
Updated at:

References

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

Frequently Asked Questions

What is the severity of CVE-2018-21029?
CVE-2018-21029 has been scored as a critical severity vulnerability.
How to fix CVE-2018-21029?
To fix CVE-2018-21029, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2018-21029 being actively exploited in the wild?
It is possible that CVE-2018-21029 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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