samba: NULL pointer de-reference in Samba AD DC LDAP server
Published Nov 28, 2018
6.5
MEDIUMCVSS 3.1
EPSS 3.25%
Description
Samba from version 4.0.0 and before versions 4.7.12, 4.8.7, 4.9.3 is vulnerable to a denial of service. During the processing of an LDAP search before Samba's AD DC returns the LDAP entries to the client, the entries are cached in a single memory object with a maximum size of 256MB. When this size is reached, the Samba process providing the LDAP service will follow the NULL pointer, terminating the process. There is no further vulnerability associated with this issue, merely a denial of service.
Affected products
- Vendor n/a Product Samba Defaultn/a
- Version 4.7.12StatusaffectedConstraints-
- Version 4.8.7StatusaffectedConstraints-
- 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 |
|
Configuration 1
Configuration 2
- 12.04
- 14.04
- 16.04
- 18.04
- 18.10
Configuration 3
- 8.0
- 9.0
No data.
Red Hat Enterprise Linux 5
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 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.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:S/C:N/I:N/A:P
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 3, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (26 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 3.25% (0.03251) | 87.92th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.25% (0.03251) | 86.67th | v5 (v2026.06.15) |
| Mar 10, 2026 | 9.20% (0.09195) | 92.57th | v4 (v2025.03.14) |
| Dec 28, 2025 | 13.55% (0.13555) | 93.99th | v4 (v2025.03.14) |
| Dec 27, 2025 | 11.72% (0.11716) | 93.49th | v4 (v2025.03.14) |
| Nov 21, 2025 | 13.55% (0.13555) | 93.95th | v4 (v2025.03.14) |
| Nov 18, 2025 | 12.21% (0.12207) | 93.16th | v4 (v2025.03.14) |
| Oct 28, 2025 | 14.00% (0.13998) | 94.02th | v4 (v2025.03.14) |
| Oct 27, 2025 | 12.11% (0.12108) | 93.52th | v4 (v2025.03.14) |
| Oct 1, 2025 | 14.00% (0.13998) | 94.13th | v4 (v2025.03.14) |
| Aug 31, 2025 | 12.31% (0.12309) | 93.61th | v4 (v2025.03.14) |
| Aug 28, 2025 | 5.60% (0.05602) | 89.95th | v4 (v2025.03.14) |
| Mar 30, 2025 | 7.16% (0.07163) | 90.70th | v4 (v2025.03.14) |
| Mar 29, 2025 | 9.62% (0.09624) | 88.04th | v4 (v2025.03.14) |
| Mar 19, 2025 | 7.16% (0.07163) | 90.45th | v4 (v2025.03.14) |
| Mar 17, 2025 | 8.59% (0.08586) | 91.77th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.70% (0.00703) | 80.99th | v3 (v2023.03.01) |
| Jun 23, 2024 | 0.70% (0.00703) | 80.41th | v3 (v2023.03.01) |
| Apr 20, 2024 | 0.90% (0.00895) | 82.46th | v3 (v2023.03.01) |
| Nov 22, 2023 | 1.24% (0.01245) | 83.96th | v3 (v2023.03.01) |
| Nov 7, 2023 | 0.98% (0.00977) | 81.76th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.76% (0.00761) | 78.31th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.28% (0.01282) | 68.34th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.28% (0.01282) | 41.72th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.57% (0.02567) | 55.02th | v5 (v2026.06.15) |
| Apr 14, 2021 | 2.57% (0.02567) | 0.00th | v1 |
References (13)
- http://www.securityfocus.com/bid/106027 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2018-16851 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1646377 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16851 x_refsource_CONFIRMIssue TrackingThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/12/msg00005.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2018-16851
- https://security.gentoo.org/glsa/202003-52 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://security.netapp.com/advisory/ntap-20181127-0001/ x_refsource_CONFIRMThird Party Advisory
- https://usn.ubuntu.com/3827-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3827-2/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-16851
- https://www.debian.org/security/2018/dsa-4345 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.samba.org/samba/security/CVE-2018-16851.html x_refsource_CONFIRMPatchVendor Advisory
Change history (0)
No recorded changes yet.