samba: Bad password count in AD DC not always effective
Published Nov 28, 2018
7.4
HIGHCVSS 3.0
EPSS 2.30%
Description
Samba from version 4.9.0 and before version 4.9.3 that have AD DC configurations watching for bad passwords (to restrict brute forcing of passwords) in a window of more than 3 minutes may not watch for bad passwords at all. The primary risk from this issue is with regards to domains that have been upgraded from Samba 4.8 and earlier. In these cases the manual testing done to confirm an organisation's password policies apply as expected may not have been re-done after the upgrade.
Affected products
- Vendor n/a Product Samba Defaultn/a
- Version 4.9.3StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Samba | n/a |
|
No data.
Red Hat Enterprise Linux 5
samba
Not affected
Red Hat Enterprise Linux 5
samba3x
Not affected
Red Hat Enterprise Linux 6
samba
Not affected
Red Hat Enterprise Linux 6
samba4
Not affected
Red Hat Enterprise Linux 7
samba
Not affected
Red Hat Enterprise Linux 8
samba
Not affected
Red Hat Storage 3
samba
Not affected
Red Hat Virtualization 4
samba
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | samba | Not affected | n/a |
| Red Hat Enterprise Linux 5 | samba3x | Not affected | n/a |
| Red Hat Enterprise Linux 6 | samba | Not affected | n/a |
| Red Hat Enterprise Linux 6 | samba4 | Not affected | n/a |
| Red Hat Enterprise Linux 7 | samba | Not affected | n/a |
| Red Hat Enterprise Linux 8 | samba | Not affected | n/a |
| Red Hat Storage 3 | samba | Not affected | n/a |
| Red Hat Virtualization 4 | samba | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This flaw does not affect the version of samba shipped with Red Hat Enterprise Linux because there is no support for samba as Active Directory Domain Controller.
Red Hat mitigation
Bad password lockout is not configured by default, it is only effective if a threshold has been set with (eg): samba-tool domain passwordsettings set --account-lockout-threshold=3 To mitigate the issue set a shorter 'Reset account lockout after' window (the ineffective default is 30, anything less than 15 will work): samba-tool domain passwordsettings set --reset-account-lockout-after=15 NOTE: If a fine-grained password policy (PSO) is set, this must also be done on each PSO.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
AV:N/AC:M/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (20 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 2.30% (0.02301) | 82.70th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.30% (0.02301) | 80.99th | v5 (v2026.06.15) |
| Mar 30, 2025 | 2.65% (0.02645) | 84.43th | v4 (v2025.03.14) |
| Mar 29, 2025 | 5.62% (0.05620) | 83.49th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.65% (0.02645) | 84.75th | v4 (v2025.03.14) |
| Jul 20, 2024 | 0.67% (0.00668) | 79.96th | v3 (v2023.03.01) |
| May 30, 2024 | 0.67% (0.00668) | 79.73th | v3 (v2023.03.01) |
| Apr 20, 2024 | 0.62% (0.00622) | 78.66th | v3 (v2023.03.01) |
| Dec 27, 2023 | 1.10% (0.01099) | 82.79th | v3 (v2023.03.01) |
| Nov 22, 2023 | 0.80% (0.00795) | 79.63th | v3 (v2023.03.01) |
| Apr 26, 2023 | 0.87% (0.00872) | 80.05th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.92% (0.00916) | 80.42th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Sep 10, 2022 | 1.02% (0.01018) | 38.88th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.02% (0.01018) | 36.86th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.02% (0.01018) | 19.50th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.25% (0.01247) | 30.57th | v1 |
| Jan 6, 2022 | 1.25% (0.01247) | 29.93th | v1 |
| Sep 1, 2021 | 1.25% (0.01247) | 68.62th | v1 |
| Apr 14, 2021 | 1.25% (0.01247) | 0.00th | v1 |
References (9)
- http://www.securityfocus.com/bid/106024 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2018-16857 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1649278 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16857 x_refsource_CONFIRMIssue TrackingMitigationThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2018-16857
- https://security.gentoo.org/glsa/202003-52 vendor-advisoryx_refsource_GENTOO
- https://security.netapp.com/advisory/ntap-20181127-0001/ x_refsource_CONFIRMThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-16857
- https://www.samba.org/samba/security/CVE-2018-16857.html x_refsource_CONFIRMMitigationPatchVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/106024 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| https://access.redhat.com/security/cve/CVE-2018-16857 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1649278 | Issue Tracking | |
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16857 | x_refsource_CONFIRMIssue TrackingMitigationThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2018-16857 | ||
| https://security.gentoo.org/glsa/202003-52 | vendor-advisoryx_refsource_GENTOO | |
| https://security.netapp.com/advisory/ntap-20181127-0001/ | x_refsource_CONFIRMThird Party Advisory | |
| https://www.cve.org/CVERecord?id=CVE-2018-16857 | ||
| https://www.samba.org/samba/security/CVE-2018-16857.html | x_refsource_CONFIRMMitigationPatchVendor Advisory |
Change history (0)
No recorded changes yet.