← Vulnerability feed

Vulnerability record · CVE-2020-17049 · published 11 November 2020

CVE-2020-17049: Microsoft windows server 2012 incorrect authorization vulnerability

Microsoft · Windows Server 2012

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.

6.6 CVSS 3.1 Medium EPSS 14% · top 3.6% CWE-863 · Incorrect authorization
6.6CVSS 3.1 base score, v2 9.0
14%EPSS exploitation probability, 30 days
NoNot in CISA KEV
4Affected product versions listed by NVD
6References
17 Jun 2026Last modified by NVD

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/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected products

4 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.openwall.com/lists/oss-security/2021/11/10/3 Mailing ListThird Party Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049 PatchVendor Advisory
https://security.gentoo.org/glsa/202309-06
http://www.openwall.com/lists/oss-security/2021/11/10/3 Mailing ListThird Party Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049 PatchVendor Advisory
https://security.gentoo.org/glsa/202309-06

Track CVE-2020-17049 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2020-1350Windows DNS Server improper input validation remote code executionWindows DNS servers fail to properly handle certain requests, allowing remote code execution. The flaw is network-reachable, needs no authentication …KEVEPSS 97%analysed9.8CVE-2026-33824Double free in Windows IKE Extension enables remote code executionA double free flaw (CWE-415) exists in the Windows IKE Extension, reachable over the network by an unauthenticated attacker. Successful exploitation …KEVEPSS 1.6%analysed9.8CVE-2025-59287Microsoft WSUS deserialization flaw allows unauthenticated remote code executionWindows Server Update Service (WSUS) deserializes untrusted data, letting an unauthenticated network attacker run code on the server. The flaw is rat…KEVEPSS 100%analysed9.8CVE-2017-8543Windows Search memory handling flaw allows remote code executionWindows Search fails to properly handle objects in memory, allowing an unauthenticated remote attacker to execute code on affected Windows systems. T…KEVEPSS 74%analysed9.8CVE-2017-7494Samba writable share library upload leads to remote code executionSamba versions from 3.5.0 up to (but not including) 4.6.4, 4.5.10 and 4.4.14 allow a malicious client to upload a shared library to a writable share …KEVEPSS 99%analysed9.8CVE-2015-1635Microsoft HTTP.sys remote code execution via crafted HTTP requestsHTTP.sys in multiple Windows versions fails to properly handle crafted HTTP requests, allowing remote code execution. The flaw is reachable over the …KEVEPSS 100%analysed9.0CVE-2020-1040Microsoft Hyper-V RemoteFX vGPU input validation remote code executionHyper-V RemoteFX vGPU on a host server fails to properly validate input from an authenticated user on a guest operating system, allowing remote code …KEVEPSS 7.4%analysed8.8CVE-2026-21510Windows Shell protection mechanism failure allows security feature bypassWindows Shell contains a protection mechanism failure (CWE-693) that lets an unauthorized attacker bypass a security feature over a network. The flaw…KEVEPSS 24%analysed

Source: NIST National Vulnerability Database (record CVE-2020-17049), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.