---
title: "CVE-2019-14870\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2019-14870?format=md
keywords: index, follow
---

# CVE-2019-14870

Publication date 10 December 2019

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**5.4 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2019-14870?format=md#impact-score)

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## 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.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| samba | 19.10 eoan | Fixed 2:4.10.7+dfsg-0ubuntu2.3 |
| 19.04 disco | Fixed 2:4.10.0+dfsg-0ubuntu2.7 |
| 18.04 LTS bionic | Fixed 2:4.7.6+dfsg~ubuntu-0ubuntu2.14 |
| 16.04 LTS xenial | Fixed 2:4.3.11+dfsg-0ubuntu0.16.04.24 |
| 14.04 LTS trusty | Fixed 2:4.3.11+dfsg-0ubuntu0.14.04.20+esm4  Ubuntu Pro |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

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## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.4 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | Low |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | Low |
  | Integrity impact | Low |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.4 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-14870)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-14870)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-14870)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-14870)

### Related Ubuntu Security Notices (USN)

+ [USN-4217-2](https://usn.ubuntu.com/USN-4217-2)
+ Samba vulnerabilities
+ 11 December 2019

+ [USN-4217-1](https://usn.ubuntu.com/USN-4217-1)
+ Samba vulnerabilities
+ 10 December 2019

### Other references

* <https://www.samba.org/samba/security/CVE-2019-14870.html>
* <https://www.cve.org/CVERecord?id=CVE-2019-14870>