Home/CVE/A Reachable Assertion issue was discovered in the KDC in MIT Kerberos 5 (aka krb5) before 1.17. If an attacker can obtai
CVE

CVE-2018-20217

A Reachable Assertion issue was discovered in the KDC in MIT Kerberos 5 (aka krb5) before 1.17. If an attacker can obtai

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.

MEDIUM · CVSS 5.3 EPSS 0.02665
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules8 YARA rules0
⬡

Weakness Classification

CWE-617Reachable Assertion
▤

Affected Products & Versions

2
mit kerberos< 5-1.17
debian linuxall versions
◈

Sigma Hunt Rules

8
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network
producthighSuspicious Kerberos Ticket Request via PowerShell Script - ScriptBlock
producthighSuspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing
producthighAttempts of Kerberos Coercion Via DNS SPN Spoofing
producthighSuspicious Kerberos Ticket Request via CLI
producthighPotential Kerberos Coercion by Spoofing SPNs via DNS Manipulation
▣

Scoring & Timeline

5.3
MEDIUM · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD26 Dec 2018 · 09:29 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
⚑

Vendor Advisories

8
suse-csafopenSUSE-SU-2024:11549-1
usnUSN-5828-1
rhsaRHBA-2020:0547Important
suse-csafSUSE-SU-2019:0113-2
suse-csafopenSUSE-SU-2019:0063-1
🔗

References & Sources

6
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8763PatchThird Party Advisory
https://github.com/krb5/krb5/commit/5e6d1796106df8ba6bc1973ee0917c170d929086PatchThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00020.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2021/09/msg00019.htmlMailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KNHELH4YHNT6H2ESJWX2UIDXLBNGB2O/
https://security.netapp.com/advisory/ntap-20190416-0006/Third Party Advisory
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