CVE-2018-16851: canonical ubuntu_linux NULL Pointer Dereference
Vulnerability summary
CVE-2018-16851 is a medium (CVSS 6.5) NULL Pointer Dereference vulnerability in canonical ubuntu_linux. EPSS estimates a 3.25% chance of exploitation in the next 30 days, higher than 88.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 6 · Related 3Timeline
- 28-11-2018PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
8 scores · 5 sources · 3 versions- OSV · AlpineEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST6.5MediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
3.25%
Chance of exploitation in the next 30 days
Percentile
88%
Versus all other CVEs
30-day change
0.00 pp
From 3.25% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- samba< 2:4.9.2+dfsg-2
- debian_linuxEOL8.0 | 9.0
[unknown]1 product
- sambaEOL4.7.12 | 4.8.7 | 4.9.3
Alpine1 product
- samba≥ 4.0.0, < 4.8.7-r0 | ≥ 4.0.0, < 4.6.16-r2 | ≥ 4.0.0, < 4.7.6-r2 | ≥ 4.0.0, < 4.8.8-r0
Canonical1 product
- ubuntu_linuxEOL12.04 | 14.04 | 16.04 | 18.04 | 18.10
Samba1 product
- samba≥ 4.0.0, < 4.7.12 | ≥ 4.8.0, < 4.8.7 | ≥ 4.9.0, < 4.9.3
Ubuntu1 product
- samba< 2:4.3.11+dfsg-0ubuntu0.14.04.19 | < 2:4.3.11+dfsg-0ubuntu0.16.04.18 | < 2:4.7.6+dfsg~ubuntu-0ubuntu2.5
6 vendors · 7 products
References
15 links
lists.debian.org/debian-lts-announce/2018/12/msg00005.htmlMailing ListX Refsource MLISTThird Party Advisory- bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16851X Refsource CONFIRMIssue TrackingThird Party Advisory