Dns ServerApplication · Synology

CVE-2017-12074

MEDIUM · 6.5 CVSS v3.0 Published 2017-08-24
Fix available
A fix is available. Upgrade to after 2.2.0-3032 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
Directory traversal vulnerability in the SYNO.DNSServer.Zone.MasterZoneConf in Synology DNS Server before 2.2.1-3042 allows remote authenticated attackers to write arbitrary files via the domain_name parameter.

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

Directory traversal vulnerability in Synology DNS Server's MasterZoneConf API allows authenticated remote attackers to write arbitrary files via the domain_name parameter using '..' path sequences. An attacker with valid DNS Server credentials can escape the intended directory and place files anywhere the web server process has write access.

MitigationUpgrade Synology DNS Server to version 2.2.1-3042 or later. Until patched, restrict access to the DNS Server management interface to trusted administrators only and monitor for unusual file creation events.

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
Dns ServerApplication
Affected:<= 2.2.0-3032

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
High
Availability
None

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

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. Confirm Synology DNS Server is installed
    Locate the DNS Server package on the Synology device via Package Center or by running 'synopkg list' from the command line
    Affected if DNS Server package is present on the system
  2. Check installed DNS Server version
    View the DNS Server package version in Package Center details, or run 'synopkg version DnsServer' or similar command to retrieve the exact version number
    Affected if Installed version is 2.2.0-3032 or any version lower than 2.2.1-3042
  3. Verify MasterZoneConf API accessibility
    Confirm the DNS Server web management interface is accessible by attempting to reach the DNS Server control panel via the Synology web interface or by checking if port 53 (DNS) management ports are exposed
    Affected if DNS Server management interface is reachable over the network
  4. Confirm authentication status
    Determine whether DNS Server administrative credentials are configured and in use, as this vulnerability requires valid credentials to exploit
    Affected if Valid DNS Server admin credentials exist and the management interface is accessible

Your environment is affected if Synology DNS Server is installed with version 2.2.0-3032 or lower AND the DNS Server management interface is accessible with valid credentials.

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.

From vendor data
Upgrade available Upgrade to a release after 2.2.0-3032
Interim mitigation

Upgrade Synology DNS Server to version 2.2.1-3042 or later. Until patched, restrict access to the DNS Server management interface to trusted administrators only and monitor for unusual file creation events.

Fix this in Dns Server 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

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2017-12074 — 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-2017-12074 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