CVE-2019-14870

NameCVE-2019-14870
DescriptionAll 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
ReferencesDLA-2668-1, DLA-3206-1
Debian Bugs946786

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
heimdal (PTS)buster7.5.0+dfsg-3vulnerable
buster (security)7.5.0+dfsg-3+deb10u1fixed
bullseye7.7.0+dfsg-2fixed
bullseye (security)7.7.0+dfsg-2+deb11u2fixed
bookworm7.7.0+dfsg-6fixed
sid7.8.git20221115.a6cf945+dfsg-3fixed
samba (PTS)buster, buster (security)2:4.9.5+dfsg-5+deb10u3vulnerable
bullseye (security), bullseye2:4.13.13+dfsg-1~deb11u5fixed
bookworm, sid2:4.17.3+dfsg-3fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
heimdalsourcebuster7.5.0+dfsg-3+deb10u1DLA-3206-1
heimdalsource(unstable)7.7.0+dfsg-1946786
sambasourcestretch2:4.5.16+dfsg-1+deb9u4DLA-2668-1
sambasource(unstable)2:4.11.3+dfsg-1

Notes

[buster] - samba <no-dsa> (Minor issue)
[jessie] - samba <no-dsa> (Minor issue)
[stretch] - heimdal <no-dsa> (Minor issue)
[jessie] - heimdal <no-dsa> (Minor issue)
https://www.samba.org/samba/security/CVE-2019-14870.html
https://github.com/heimdal/heimdal/security/advisories/GHSA-q77c-9qvp-qfw4
https://github.com/heimdal/heimdal/pull/663
https://github.com/heimdal/heimdal/pull/664 (port to 7.1 branch)
https://github.com/heimdal/heimdal/commit/0495a19a938ad68283078e62c659e4f1c5980815 (heimdal-7.7.1)
https://github.com/heimdal/heimdal/commit/bdd1d0227720c252771f2db65c31f02bc9fc493c (heimdal-7.7.1)
https://github.com/heimdal/heimdal/commit/fd43016f2f4b58cf4f0cf3f47b2541f2ab11b2b8 (heimdal-7.7.1)

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