dbcve.org
Dns ServerApplication · Synology

CVE-2022-27615

HIGH · 8.1 CVSS v3.1 Published 2022-07-28
Fix available
A fix is available. Upgrade to 2.2.2-5027 or later.
See remediation →
87/100
Remediation priority · High
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
Improper limitation of a pathname to a restricted directory ('Path Traversal') vulnerability in cgi component in Synology DNS Server before 2.2.2-5027 allows remote authenticated users to delete arbitrary files via unspecified vectors.

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

A Path Traversal vulnerability exists in the CGI component of Synology DNS Server versions prior to 2.2.2-5027. The flaw allows remote authenticated users to manipulate file paths to delete arbitrary files on the system through the web CGI interface, bypassing directory restrictions.

MitigationUpgrade Synology DNS Server to version 2.2.2-5027 or later to apply the vendor patch. If immediate patching is not possible, restrict CGI component access to only trusted authenticated users and monitor for unauthorized file deletion attempts.

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:< 2.2.2-5027

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
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/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. Confirm Synology DNS Server installation
    Locate the Synology DNS Server package on the system. On Synology NAS devices, check via Package Center or by locating the installation path (typically /volumeX/@appstore/dnsserver/).
    Affected if Synology DNS Server is not installed on the system.
  2. Identify installed DNS Server version
    Access the DNS Server web interface (typically port 5001 or 5000), navigate to the control panel or about section, and record the version number. Alternatively, check via command line using 'cat /etc.defaults/VERSION' or the package manifest.
    Affected if The installed version is lower than 2.2.2-5027.
  3. Verify CGI component status
    Check if the web CGI interface for DNS Server is enabled. This is typically accessible via the DNS Server web interface under Web Services or CGI settings. Inspect the configuration file (if accessible) for CGI module enablement.
    Affected if The CGI component is exposed and accessible via the web interface.
  4. Review user access controls
    Examine the DNS Server user management settings to determine which authenticated users have access to the CGI functionality. Check for any unauthorized or unexpected user accounts with administrative privileges.
    Affected if Untrusted or unauthorized authenticated users have access to the DNS Server CGI interface.
  5. Inspect logs for file deletion attempts
    Review Synology system logs and DNS Server application logs (typically in /var/log/synologaccess or the DNS Server log directory) for patterns indicating path traversal deletion attempts, such as ../../../ sequences or deletion of files outside the expected data directory.

A system is affected if Synology DNS Server is installed with a version prior to 2.2.2-5027 and the CGI component is accessible to 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 2.2.2-5027 or later
Fixed in 2.2.2-5027
Interim mitigation

Upgrade Synology DNS Server to version 2.2.2-5027 or later to apply the vendor patch. If immediate patching is not possible, restrict CGI component access to only trusted authenticated users and monitor for unauthorized file deletion attempts.

Recommended fix High confidence

2.2.2-5027

  1. 1. Log into Synology DSM as administrator
  2. 2. Open Package Center
  3. 3. Locate Synology DNS Server in the installed package list
  4. 4. Click on the package and select 'Update' to check for available updates
  5. 5. Update to version 2.2.2-5027 or later
  6. 6. Alternatively, manually download the update from Synology Download Center and install via Manual Install in Package Center
  7. 7. After update, verify the new version is 2.2.2-5027 or higher

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

Fix this in Dns Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

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-2022-27615 in production — separate from our analysis above.

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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