{
    "id": "CVE-2018-21029",
    "published": "2019-10-30 22:15:10",
    "last_modified": "2026-06-17 01:53:59",
    "cvss_score": "9.8",
    "cvss_severity": "CRITICAL",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
    "cwe": "CWE-295",
    "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)",
    "epss_score": "0.03138",
    "epss_percentile": "0.87544",
    "kev": 0,
    "kev_due": null,
    "has_exploit": 0,
    "updated_at": "2026-10-10 18:17:18",
    "priority": {
        "rank": 3,
        "label": "In your normal cycle",
        "why": "Critical by CVSS (9.8), but no sign of active exploitation."
    },
    "products": [
        {
            "vendor": "fedoraproject",
            "product": "fedora"
        },
        {
            "vendor": "systemd_project",
            "product": "systemd"
        }
    ],
    "kev_detail": null,
    "exploits": [],
    "refs_list": [
        "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"
    ]
}