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 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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
5.3 MEDIUM
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
mitreCNA
---
---
CVEADP
---
---
Base Score
CVSS 3.x
EPSS Score
Percentile: 81%
VendorProductVersion
mitkerberos
𝑥
< 5-1.17
debiandebian_linux
8.0
debiandebian_linux
9.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
krb5
bullseye (security)
1.18.3-6+deb11u5
fixed
bullseye
1.18.3-6+deb11u5
fixed
bookworm
1.20.1-2+deb12u2
fixed
bookworm (security)
1.20.1-2+deb12u2
fixed
sid
1.21.3-3
fixed
trixie
1.21.3-3
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
krb5
kinetic
not-affected
jammy
not-affected
impish
not-affected
hirsute
not-affected
groovy
not-affected
focal
not-affected
eoan
ignored
disco
ignored
cosmic
ignored
bionic
Fixed 1.16-2ubuntu0.3
released
xenial
Fixed 1.13.2+dfsg-5ubuntu2.2+esm3
released
trusty
Fixed 1.12+dfsg-2ubuntu5.4+esm1
released
Common Weakness Enumeration
References
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8763
https://github.com/krb5/krb5/commit/5e6d1796106df8ba6bc1973ee0917c170d929086
https://lists.debian.org/debian-lts-announce/2019/01/msg00020.html
https://lists.debian.org/debian-lts-announce/2021/09/msg00019.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KNHELH4YHNT6H2ESJWX2UIDXLBNGB2O/
https://security.netapp.com/advisory/ntap-20190416-0006/
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8763
https://github.com/krb5/krb5/commit/5e6d1796106df8ba6bc1973ee0917c170d929086
https://lists.debian.org/debian-lts-announce/2019/01/msg00020.html
https://lists.debian.org/debian-lts-announce/2021/09/msg00019.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KNHELH4YHNT6H2ESJWX2UIDXLBNGB2O/
https://security.netapp.com/advisory/ntap-20190416-0006/