dbcve.org
FedoraOperating system · Fedoraproject

CVE-2020-25718

HIGH · 8.8 CVSS v3.1 Published 2022-02-18
Fix available
A fix is available. Upgrade to 4.13.14 / 4.14.10 or later.
See remediation →
94/100
Remediation priority · Urgent
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 flaw was found in the way samba, as an Active Directory Domain Controller, is able to support an RODC (read-only domain controller). This would allow an RODC to print administrator tickets.

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 · high confidence

CVE-2020-25718 is a vulnerability in Samba when acting as an Active Directory Domain Controller. The flaw allows a Read-Only Domain Controller (RODC) to print administrator tickets, which should not be permitted since RODCs are designed to be read-only and should not issue or handle Kerberos service tickets for administrative accounts. This represents a privilege escalation and authorization bypass issue in the RODC functionality.

MitigationUpdate Samba to the patched version that properly restricts RODC from printing administrator tickets. Additionally, review and restrict RODC replication and privilege assignments to enforce read-only behavior per Microsoft best practices for RODC deployment.

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
FedoraOperating system
Affected:= 35
SambaApplication
Affected:>= 4.0.0, < 4.13.14>= 4.14.0, < 4.14.10>= 4.15.0, < 4.15.2

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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. Check installed Samba version
    Run 'smbd --version' or 'samba --version' to retrieve the installed Samba version number
    Affected if The version falls within any of these ranges: >= 4.0.0 and < 4.13.14, >= 4.14.0 and < 4.14.10, or >= 4.15.0 and < 4.15.2
  2. Verify Samba is running as Domain Controller
    Check /etc/samba/smb.conf for 'server role = active directory domain controller' or inspect running processes for 'samba' domain controller services
    Affected if Samba is configured and running as an Active Directory Domain Controller
  3. Confirm Read-Only Domain Controller configuration
    Inspect smb.conf for RODC-specific settings such as 'read only = Yes', 'server role', or run 'samba-tool domain info 127.0.0.1' to query DC type
    Affected if The Samba DC is configured as a Read-Only Domain Controller (RODC)
  4. Check for RODC replication of privileged accounts
    Review AD replication status using 'samba-tool drs show' or check if any administrative accounts have been replicated to the RODC
    Affected if Privileged or administrative accounts exist on or are accessible to the RODC

The environment is affected if Samba is running as an RODC with a version in the affected ranges and privileged accounts can be queried or served by the RODC, allowing unauthorized ticket issuance.

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 4.13.14 / 4.14.10 / 4.15.2 or later
Fixed in 4.13.144.14.104.15.2
Interim mitigation

Update Samba to the patched version that properly restricts RODC from printing administrator tickets. Additionally, review and restrict RODC replication and privilege assignments to enforce read-only behavior per Microsoft best practices for RODC deployment.

Recommended fix High confidence

Samba: 4.13.14 or later, 4.14.10 or later, or 4.15.2 or later (depending on your current branch)

  1. 1. Back up your Samba configuration and database before upgrading
  2. 2. For package-based systems (e.g., Fedora, Debian, RHEL): Update the samba package using your system's package manager (e.g., 'dnf update samba' or 'apt-get update && apt-get install samba')
  3. 3. Verify the installed version matches or exceeds the minimum fixed version for your release branch
  4. 4. If running as an Active Directory Domain Controller, restart the samba service (e.g., 'systemctl restart samba')
  5. 5. Test that the RODC functionality works correctly after the upgrade
Caveat Review Samba release notes for your version jump for any migration requirements; major version upgrades may require configuration adjustments

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

Fix this in Fedora Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-25718 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-25718 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