CVE-2020-17049
Kerberos KDC Security Feature Bypass Vulnerability
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
<p>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).</p>
<p>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.</p>
<p>The update addresses this vulnerability by changing how the KDC validates service tickets used with KCD.</p>
Vulnerabilidad de Omisión de la CaracterÃstica de Seguridad de Kerberos
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.
It was found that the Kerberos Key Distribution Center (KDC) delegation feature, Service for User (S4U), did not sufficiently protect the tickets it's providing from tempering. A malicious, authenticated service principal allowed to delegate could use this flaw to impersonate a non-forwardable user.
CVSS Scores
SSVC
- Decision:Track*
Timeline
- 2020-08-04 CVE Reserved
- 2020-11-11 CVE Published
- 2024-07-11 EPSS Updated
- 2024-11-15 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-345: Insufficient Verification of Data Authenticity
- CWE-863: Incorrect Authorization
CAPEC
References (5)
| URL | Tag | Source |
|---|---|---|
| http://www.openwall.com/lists/oss-security/2021/11/10/3 | Mailing List |
|
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17049 | 2023-12-31 |
| URL | Date | SRC |
|---|---|---|
| https://security.gentoo.org/glsa/202309-06 | 2023-12-31 | |
| https://access.redhat.com/security/cve/CVE-2020-17049 | 2024-01-15 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2025721 | 2024-01-15 |
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Microsoft Search vendor "Microsoft" | Windows Server 2012 Search vendor "Microsoft" for product "Windows Server 2012" | * | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2012 Search vendor "Microsoft" for product "Windows Server 2012" | r2 Search vendor "Microsoft" for product "Windows Server 2012" and version "r2" | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2016 Search vendor "Microsoft" for product "Windows Server 2016" | - | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2016 Search vendor "Microsoft" for product "Windows Server 2016" | 20h2 Search vendor "Microsoft" for product "Windows Server 2016" and version "20h2" | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2016 Search vendor "Microsoft" for product "Windows Server 2016" | 1903 Search vendor "Microsoft" for product "Windows Server 2016" and version "1903" | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2016 Search vendor "Microsoft" for product "Windows Server 2016" | 1909 Search vendor "Microsoft" for product "Windows Server 2016" and version "1909" | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2016 Search vendor "Microsoft" for product "Windows Server 2016" | 2004 Search vendor "Microsoft" for product "Windows Server 2016" and version "2004" | - |
Affected
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| Microsoft Search vendor "Microsoft" | Windows Server 2019 Search vendor "Microsoft" for product "Windows Server 2019" | - | - |
Affected
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| Samba Search vendor "Samba" | Samba Search vendor "Samba" for product "Samba" | >= 4.1.0 < 4.13.13 Search vendor "Samba" for product "Samba" and version " >= 4.1.0 < 4.13.13" | - |
Affected
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| Samba Search vendor "Samba" | Samba Search vendor "Samba" for product "Samba" | >= 4.14.0 < 4.14.9 Search vendor "Samba" for product "Samba" and version " >= 4.14.0 < 4.14.9" | - |
Affected
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| Samba Search vendor "Samba" | Samba Search vendor "Samba" for product "Samba" | >= 4.15.0 < 4.15.1 Search vendor "Samba" for product "Samba" and version " >= 4.15.0 < 4.15.1" | - |
Affected
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