{"cve":"CVE-2020-17049","nvd":{"published":"2020-11-11T07:15:16.543","modified":"2026-06-17T02:58:34.727","status":"Modified","description":"A security feature bypass vulnerability exists in the way Key Distribution Center (KDC) determines if a service ticket can be used for delegation via Kerberos Constrained Delegation (KCD).\nTo exploit the vulnerability, a compromised service that is configured to use KCD could tamper with a service ticket that is not valid for delegation to force the KDC to accept it.\nThe update addresses this vulnerability by changing how the KDC validates service tickets used with KCD.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H","score":6.6},"cwes":["CWE-863"],"references":["http://www.openwall.com/lists/oss-security/2021/11/10/3","https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049","https://security.gentoo.org/glsa/202309-06","http://www.openwall.com/lists/oss-security/2021/11/10/3","https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049"],"products":["microsoft:windows_server_2012","microsoft:windows_server_2016","microsoft:windows_server_2019","samba:samba"],"source":"nvd","synced_at":"2026-10-19T21:11:20.317016139+00:00"},"epss":{"cve":"CVE-2020-17049","score":0.13794,"percentile":0.96518,"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."]}