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SambaApplication

CVE-2023-5568

MEDIUM · 6.5 CVSS v3.1 Published 2023-10-25
Fix available
A fix is available. Upgrade to 4.19.2 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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 heap-based Buffer Overflow flaw was discovered in Samba. It could allow a remote, authenticated attacker to exploit this vulnerability to cause a denial of service.

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 · moderate confidence

A heap-based buffer overflow vulnerability exists in Samba that can be exploited by a remote, authenticated attacker. The vulnerability allows the attacker to trigger the overflow condition, potentially leading to denial of service. Successful exploitation does not appear to provide code execution based on the CVSS scope indicating DoS as the impact.

MitigationApply the relevant Samba security patch or update to a version that addresses CVE-2023-5568. For systems where immediate patching is not feasible, consider network segmentation and restricting authenticated access to Samba services to minimize attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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:< 4.19.2

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
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Samba is installed
    Run 'smbd --version' or check installed packages with your package manager (dpkg -l | grep samba, rpm -qa | grep samba, etc.)
    Affected if Samba is installed and the version is below 4.19.2
  2. Determine the exact Samba version
    Execute 'smbd --version' or 'samba --version' to get the precise version number
    Affected if The reported version is less than 4.19.2 (e.g., 4.18.x, 4.17.x, etc.)
  3. Confirm Samba network listeners are active
    Run 'netstat -tlnp | grep -E "smbd|nmbd|winbind"' or 'ss -tlnp | grep -E "smbd|nmbd|winbind"' to see which interfaces Samba is listening on
    Affected if Samba is bound to non-loopback interfaces (0.0.0.0 or external IP addresses)
  4. Check SMB/CIFS port accessibility
    Test connectivity to ports 445 and 139 using 'nc -zv <target> 445' or 'nmap -p 445,139 <target>' from an external system
    Affected if Ports 445 or 139 are exposed to untrusted networks or accessible remotely

You are affected if Samba is running with a version below 4.19.2 and the service is accessible to remote authenticated users.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 4.19.2 or later
Fixed in 4.19.2
Interim mitigation

Apply the relevant Samba security patch or update to a version that addresses CVE-2023-5568. For systems where immediate patching is not feasible, consider network segmentation and restricting authenticated access to Samba services to minimize attack surface.

Recommended fix Moderate confidence

Samba 4.19.2 or later

  1. 1. Backup current Samba configuration files (smb.conf) and user databases
  2. 2. Identify the current Samba version installed (e.g., smbd --version or rpm -q samba)
  3. 3. Update package repository metadata
  4. 4. Upgrade Samba packages to version 4.19.2 or later using system package manager (e.g., apt-get install samba or yum update samba)
  5. 5. Verify the new version is installed correctly (smbd --version)
  6. 6. Review and apply any configuration changes required for the new version
  7. 7. Restart Samba services (smbd, nmbd, winbindd)
  8. 8. Test that file sharing and authentication functionality works correctly
Caveat Review release notes for potential configuration or feature changes between versions; major version upgrades may require additional migration steps

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

Fix this in Samba Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

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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-2023-5568 in production — separate from our analysis above.

No notes yet

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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