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Vulnerability details: VCID-afuq-vsw6-cycu
Vulnerability ID VCID-afuq-vsw6-cycu
Aliases CVE-2018-16851
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-476 NULL Pointer Dereference
System Score Found at
cvssv3 6.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-16851.json
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.07163 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12108 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12108 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12108 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12108 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12108 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12108 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12309 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12309 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
epss 0.12309 https://api.first.org/data/v1/epss?cve=CVE-2018-16851
cvssv3 6.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 4.0 https://nvd.nist.gov/vuln/detail/CVE-2018-16851
cvssv3.1 6.5 https://nvd.nist.gov/vuln/detail/CVE-2018-16851
archlinux High https://security.archlinux.org/AVG-823
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-16851.json
https://api.first.org/data/v1/epss?cve=CVE-2018-16851
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16851
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-14629
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-16841
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-16851
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://lists.debian.org/debian-lts-announce/2018/12/msg00005.html
https://security.netapp.com/advisory/ntap-20181127-0001/
https://www.debian.org/security/2018/dsa-4345
https://www.samba.org/samba/security/CVE-2018-16851.html
http://www.securityfocus.com/bid/106027
1646377 https://bugzilla.redhat.com/show_bug.cgi?id=1646377
ASA-201811-22 https://security.archlinux.org/ASA-201811-22
AVG-823 https://security.archlinux.org/AVG-823
cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
CVE-2018-16851 https://nvd.nist.gov/vuln/detail/CVE-2018-16851
USN-3827-1 https://usn.ubuntu.com/3827-1/
USN-3827-2 https://usn.ubuntu.com/3827-2/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2018-16851.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:L/Au:S/C:N/I:N/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2018-16851
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2018-16851
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.91173
EPSS Score 0.07163
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:37:47.163838+00:00 Ubuntu USN Importer Import https://usn.ubuntu.com/3827-1/ 37.0.0