PublicDateAtUSN: 2019-12-10
Candidate: CVE-2019-14870
CRD: 2019-12-10
PublicDate: 2019-12-10 23:15:00 UTC
References: 
 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-14870
 https://www.samba.org/samba/security/CVE-2019-14870.html
 https://ubuntu.com/security/notices/USN-4217-1
 https://ubuntu.com/security/notices/USN-4217-2
Description:
 All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x
 before 4.11.3 have an issue, where the S4U (MS-SFU) Kerberos delegation
 model includes a feature allowing for a subset of clients to be opted out
 of constrained delegation in any way, either S4U2Self or regular Kerberos
 authentication, by forcing all tickets for these clients to be
 non-forwardable. In AD this is implemented by a user attribute
 delegation_not_allowed (aka not-delegated), which translates to
 disallow-forwardable. However the Samba AD DC does not do that for S4U2Self
 and does set the forwardable flag even if the impersonated client has the
 not-delegated flag set.
Ubuntu-Description: 
Notes: 
Mitigation: 
Bugs: 
 https://bugzilla.samba.org/show_bug.cgi?id=14187
Priority: medium
Discovered-by: Isaac Boukris
Assigned-to: mdeslaur
CVSS:
 nvd: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N [5.4 MEDIUM]


Patches_samba:
upstream_samba: released (4.11.3,4.10.11,4.9.17)
precise/esm_samba: not-affected
trusty_samba: ignored (out of standard support)
trusty/esm_samba: released (2:4.3.11+dfsg-0ubuntu0.14.04.20+esm4)
xenial_samba: released (2:4.3.11+dfsg-0ubuntu0.16.04.24)
esm-infra/xenial_samba: released (2:4.3.11+dfsg-0ubuntu0.16.04.24)
bionic_samba: released (2:4.7.6+dfsg~ubuntu-0ubuntu2.14)
disco_samba: released (2:4.10.0+dfsg-0ubuntu2.7)
eoan_samba: released (2:4.10.7+dfsg-0ubuntu2.3)
devel_samba: released (2:4.11.5+dfsg-1ubuntu1)