CVE-2020-17049
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).
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 13.8%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.
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). To 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. The update addresses this vulnerability by changing how the KDC validates service tickets used with KCD.
- CVSS 3.1
- 6.6 MEDIUMCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 13.79% probability · 96th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Affected
- microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · samba/samba
- Source
- secure@microsoft.com
EPSS 13.8% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.openwall.com/lists/oss-security/2021/11/10/3Mailing List, Third Party Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049Patch, Vendor Advisory
- https://security.gentoo.org/glsa/202309-06
- http://www.openwall.com/lists/oss-security/2021/11/10/3Mailing List, Third Party Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049Patch, Vendor Advisory
- https://security.gentoo.org/glsa/202309-06
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.