systemd: incorrect certificate validation results in acceptance of any certificate signed by a trusted certificate authority for DNS over TLS
Published Oct 30, 2019
9.8
CRITICALCVSS 3.1
EPSS 3.14%
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)
Affected products
No data.
Configuration 1
- ≥ 239 · < 244
Configuration 2
- 31
No data.
Red Hat Enterprise Linux 7
systemd
Not affected
Red Hat Enterprise Linux 8
systemd
Not affected
Red Hat OpenShift Container Platform 4
systemd
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | systemd | Not affected | n/a |
| Red Hat Enterprise Linux 8 | systemd | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | systemd | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Versions of systemd as shipped with Red Hat Enterprise Linux 7 are not affected by this issue as they did not include support for DNSOverTLS option. Versions of systemd as shipped with Red Hat Enterprise Linux 8 are not affected by this issue as they did not support the `yes` value of the DNSOverTLS option. OpenShift Container Platform 4.1 ships a version of systemd from Red Hat Enterprise Linux 8 and is thus also not affected by this issue.
References (13)
- https://access.redhat.com/security/cve/CVE-2018-21029 Vendor Advisory
- https://blog.cloudflare.com/dns-encryption-explained/ x_refsource_MISCThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1771725 Issue Tracking
- https://github.com/systemd/systemd/blob/v239/man/resolved.conf.xml#L199-L207 x_refsource_MISCExploitThird Party Advisory
- https://github.com/systemd/systemd/blob/v243/man/resolved.conf.xml#L196-L207 x_refsource_MISCExploitThird Party Advisory
- https://github.com/systemd/systemd/blob/v243/src/resolve/resolved-dnstls-gnutls.c#L62-L63 x_refsource_MISCPatchThird Party Advisory
- https://github.com/systemd/systemd/issues/9397 x_refsource_MISCIssue TrackingThird Party Advisory
- https://github.com/systemd/systemd/pull/13870 x_refsource_MISCPatchThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4NLJVOJMB6ANDILRLDZK26YGLYBEPHKY/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2018-21029
- https://security.netapp.com/advisory/ntap-20191122-0002/ x_refsource_CONFIRMThird Party Advisory
- https://tools.ietf.org/html/rfc7858#section-4.1 x_refsource_MISCThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-21029
Change history (0)
No recorded changes yet.