{"cve":"CVE-2018-20217","nvd":{"published":"2018-12-26T21:29:02.543","modified":"2026-06-17T01:52:28.013","status":"Modified","description":"A Reachable Assertion issue was discovered in the KDC in MIT Kerberos 5 (aka krb5) before 1.17. If an attacker can obtain a krbtgt ticket using an older encryption type (single-DES, triple-DES, or RC4), the attacker can crash the KDC by making an S4U2Self request.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.3},"cwes":["CWE-617"],"references":["http://krbdev.mit.edu/rt/Ticket/Display.html?id=8763","https://github.com/krb5/krb5/commit/5e6d1796106df8ba6bc1973ee0917c170d929086","https://lists.debian.org/debian-lts-announce/2019/01/msg00020.html","https://lists.debian.org/debian-lts-announce/2021/09/msg00019.html","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KNHELH4YHNT6H2ESJWX2UIDXLBNGB2O/"],"products":["debian:debian_linux","mit:kerberos"],"source":"nvd","synced_at":"2026-10-19T20:54:36.112582389+00:00"},"epss":{"cve":"CVE-2018-20217","score":0.01417,"percentile":0.72786,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}