CVE-2019-3870

Exp

A vulnerability was found in Samba from version (including) 4.9 to versions before 4.9.6 and 4.10.2. During the creation of a new Samba AD DC, files are created in a private subdirectory of the install location. This directory is typically mode 0700, that is owner (root) only access. However in some upgraded installations it will have other permissions, such as 0755, because this was the default before Samba 4.8. Within this directory, files are created with mode 0666, which is world-writable, including a sample krb5.conf, and the list of DNS names and servicePrincipalName values to update.

Published: 2019-04-09 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-3870 is rated Exploit Available (53.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.55%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2019-3870

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-3870

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.55% 0.55% +0.00%
2 2026-03-10 0.57% 0.55% -0.02%
3 2026-02-26 — 0.57% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-3870

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 4.2 [email protected]
6.1 3.0 MEDIUM
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 4.2 [email protected]
3.6 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 4.9 [email protected]

Weakness enumeration for CVE-2019-3870

OS Trackers for CVE-2019-3870

vendor priority summary link
debian not yet assigned CVE-2019-3870 not yet assigned priority: Debian including 1 source packages (samba), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-3870
redhat medium — https://access.redhat.com/security/cve/CVE-2019-3870
ubuntu medium CVE-2019-3870 medium priority: Ubuntu including 1 source packages (samba), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): not-affected 4, released 1. https://ubuntu.com/security/CVE-2019-3870

Affected software / configurations for CVE-2019-3870

Vendor Product Version Raw CPE
samba samba >= 4.9.0, < 4.9.6 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
samba samba >= 4.10.0, < 4.10.2 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
fedoraproject fedora 29 cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*
fedoraproject fedora 30 cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
synology directory_server — cpe:2.3:a:synology:directory_server:-:*:*:*:*:*:*:*
synology router_manager 1.2 cpe:2.3:a:synology:router_manager:1.2:*:*:*:*:*:*:*
synology diskstation_manager 5.2 cpe:2.3:o:synology:diskstation_manager:5.2:*:*:*:*:*:*:*
synology diskstation_manager 6.1 cpe:2.3:o:synology:diskstation_manager:6.1:*:*:*:*:*:*:*
synology diskstation_manager 6.2 cpe:2.3:o:synology:diskstation_manager:6.2:*:*:*:*:*:*:*
synology skynas_firmware — cpe:2.3:o:synology:skynas_firmware:-:*:*:*:*:*:*:*
synology vs960hd_firmware < 2.3.6-1720 cpe:2.3:o:synology:vs960hd_firmware:*:*:*:*:*:*:*:*

References for CVE-2019-3870

cvelogic Threat Intelligence