Router ManagerApplication · Synology

CVE-2018-8918

MEDIUM · 5.4 CVSS v3.0 Published 2018-12-24
Fix available
A fix is available. Upgrade to 1.1.7-6941 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

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
Cross-site scripting (XSS) vulnerability in info.cgi in Synology Router Manager (SRM) before 1.1.7-6941 allows remote attackers to inject arbitrary web script or HTML via the host 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

A cross-site scripting (XSS) vulnerability exists in the info.cgi web script of Synology Router Manager (SRM) where the 'host' parameter is not properly sanitized, allowing remote attackers to inject arbitrary JavaScript or HTML that executes in the browser sessions of other users who access the affected page.

MitigationUpgrade Synology Router Manager to version 1.1.7-6941 or later to obtain the patched code. If immediate patching is not feasible, restrict network access to the SRM management interface to trusted users only.

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
Router ManagerApplication
Affected:< 1.1.7-6941

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 Router Manager is installed
    Access the router's admin interface or check system information to verify SRM is running. Look for 'Synology Router Manager' or 'SRM' in the product name/version display.
    Affected if The device is not running Synology Router Manager, this CVE does not apply.
  2. Check the SRM version number
    In the SRM web interface, go to Control Panel > System > Information or check the version displayed on the login page or in the system status. Note the full version string (e.g., 1.1.7-6918).
    Affected if The installed version is lower than 1.1.7-6941 (e.g., 1.1.7-6918, 1.1.6, etc.). Compare the version numerically.
  3. Verify info.cgi is accessible
    Access the SRM web interface and navigate to pages that use info.cgi, or attempt to access https://[router-ip]/cgi-bin/info.cgi?host=test directly in a browser while authenticated.
    Affected if The info.cgi script is accessible and responds to requests with the 'host' parameter.
  4. Confirm the host parameter is not sanitized
    If you have access to the SRM file system via SSH or the File Station, locate info.cgi and examine how the 'host' parameter is handled in the code. Look for sanitization functions or lack thereof.
    Affected if The code does not properly sanitize or escape the 'host' parameter before reflecting it in the output.

You are affected if the device runs Synology Router Manager with a version lower than 1.1.7-6941 and the info.cgi script with the vulnerable 'host' parameter is accessible.

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 1.1.7-6941 or later
Fixed in 1.1.7-6941
Interim mitigation

Upgrade Synology Router Manager to version 1.1.7-6941 or later to obtain the patched code. If immediate patching is not feasible, restrict network access to the SRM management interface to trusted users only.

Fix this in Router Manager Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,832.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-8918 — 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-2018-8918 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