CVE-2018-20217
Ubuntu Security Notice USN-5828-1
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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.
Se ha descubierto un problema de aserción alcanzable en el KDC en MIT Kerberos 5 (también conocido como krb5), en versiones anteriores a la 1.17. Si un atacante puede obtener un ticket krbtgt mediante un tipo de cifrado más antiguo (DES, Triple DES o RC4), este puede provocar el cierre inesperado de KDC realizando una petición S4U2Self.
It was discovered that Kerberos incorrectly handled certain S4U2Self requests. An attacker could possibly use this issue to cause a denial of service. This issue was only addressed in Ubuntu 16.04 ESM and Ubuntu 18.04 LTS. Greg Hudson discovered that Kerberos PAC implementation incorrectly handled certain parsing operations. A remote attacker could use this issue to cause a denial of service, or possibly execute arbitrary code.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2018-12-19 CVE Reserved
- 2018-12-26 CVE Published
- 2024-08-05 CVE Updated
- 2025-04-29 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-617: Reachable Assertion
CAPEC
References (6)
| URL | Tag | Source |
|---|---|---|
| https://lists.debian.org/debian-lts-announce/2019/01/msg00020.html | Mailing List |
|
| https://lists.debian.org/debian-lts-announce/2021/09/msg00019.html | Mailing List |
|
| https://security.netapp.com/advisory/ntap-20190416-0006 | Third Party Advisory |
|
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| http://krbdev.mit.edu/rt/Ticket/Display.html?id=8763 | 2023-11-07 | |
| https://github.com/krb5/krb5/commit/5e6d1796106df8ba6bc1973ee0917c170d929086 | 2023-11-07 |
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Mit Search vendor "Mit" | Kerberos Search vendor "Mit" for product "Kerberos" | < 5-1.17 Search vendor "Mit" for product "Kerberos" and version " < 5-1.17" | - |
Affected
| ||||||
| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 8.0 Search vendor "Debian" for product "Debian Linux" and version "8.0" | - |
Affected
| ||||||
| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 9.0 Search vendor "Debian" for product "Debian Linux" and version "9.0" | - |
Affected
| ||||||