SambaApplication

CVE-2023-4154

MEDIUM · 6.5 CVSS v3.1 Published 2023-11-07
Fix available
A fix is available. Upgrade to 4.17.12 / 4.18.8 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A design flaw was found in Samba's DirSync control implementation, which exposes passwords and secrets in Active Directory to privileged users and Read-Only Domain Controllers (RODCs). This flaw allows RODCs and users possessing the GET_CHANGES right to access all attributes, including sensitive secrets and passwords. Even in a default setup, RODC DC accounts, which should only replicate some passwords, can gain access to all domain secrets, including the vital krbtgt, effectively eliminating the RODC / DC distinction. Furthermore, the vulnerability fails to account for error conditions (fail open), like out-of-memory situations, potentially granting access to secret attributes, even under low-privileged attacker influence.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-787

The program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.

General guidance for the out-of-bounds write class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SambaApplication
Affected:>= 4.0.0, < 4.17.12>= 4.18.0, < 4.18.8>= 4.19.0, < 4.19.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.17.12 / 4.18.8 / 4.19.1 or later
Fixed in 4.17.124.18.84.19.1
Vendor patch bugzilla.samba.org →
Recommended fix High confidence

Upgrade to Samba 4.17.12, 4.18.8, 4.19.1, or a later stable release (e.g., 4.19.2 or 4.18.9+)

  1. Identify the current Samba version by running 'samba --version' or checking the package manager
  2. Review the release notes for the target version (4.17.12, 4.18.8, or 4.19.1 and later) for any migration requirements
  3. Backup the current Samba configuration (/etc/samba/smb.conf) and all Samba database directories (/var/lib/samba)
  4. Stop all Samba services (smbd, nmbd, winbindd) before upgrading
  5. Upgrade Samba to the fixed version using the package manager (e.g., 'apt-get install samba' or 'yum update samba') or by compiling from source
  6. Verify the installed version matches the fixed release: 'samba --version'
  7. Start Samba services and verify normal operation
  8. Test that the DirSync control now properly restricts access to secret attributes
Caveat Review Samba release notes for any configuration changes or deprecated features; ensure backup and test restore procedures are in place before production upgrade

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,850. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-4154 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-4154 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data