The validate_as_request function in kdc_util.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrict_anonymous_to_tgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8458
http://lists.opensuse.org/opensuse-updates/2016-09/msg00035.html
http://rhn.redhat.com/errata/RHSA-2016-2591.html
http://web.mit.edu/kerberos/krb5-1.13/
http://web.mit.edu/kerberos/krb5-1.14/
http://www.securityfocus.com/bid/92132
http://www.securitytracker.com/id/1036442
https://github.com/krb5/krb5/commit/93b4a6306a0026cf1cc31ac4bd8a49ba5d034ba7
https://lists.debian.org/debian-lts-announce/2018/01/msg00040.html
Source: MITRE
Published: 2016-08-01
Updated: 2020-01-21
Type: CWE-476
Base Score: 4
Vector: AV:N/AC:L/Au:S/C:N/I:N/A:P
Impact Score: 2.9
Exploitability Score: 8
Severity: MEDIUM
Base Score: 6.5
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 2.8
Severity: MEDIUM