CVE-2018-8877
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 · uneditedInformation disclosure in Asuswrt-Merlin firmware for ASUS devices older than 384.4 and ASUS firmware before 3.0.0.4.382.50470 for devices allows remote attackers to acquire information on internal network IP address ranges by reading the new_lan_ip variable on the error_page.htm page.
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 confidenceThe vulnerability allows unauthenticated remote attackers to retrieve internal network IP address ranges from the new_lan_ip variable displayed on the error_page.htm page in Asuswrt-Merlin firmware versions prior to 384.4 and ASUS firmware versions before 3.0.0.4.382.50470. This information disclosure occurs because the error page exposes LAN configuration details without proper access controls.
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< 3.0.0.4.382.50470< 384.4CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify your firmware type and versionAccess the router's web administration interface or check the system information page to determine if you are running Asuswrt-Merlin or ASUS stock firmware, and note the exact firmware version number displayed.Affected if The firmware is Asuswrt-Merlin version below 384.4, or ASUS firmware below 3.0.0.4.382.50470.
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Locate the error pageAttempt to access the error_page.htm file through the router's web interface. This is typically found at a URL path like /error_page.htm or similar error handling pages.Affected if The error page is accessible without authentication.
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Inspect for new_lan_ip variable exposureExamine the error_page.htm page source or rendered content for the new_lan_ip variable or any displayed LAN configuration details such as internal IP address ranges.Affected if The new_lan_ip variable or internal LAN IP addresses are visible on the error page.
You are affected if your router runs Asuswrt-Merlin below version 384.4 or ASUS firmware below 3.0.0.4.382.50470 AND the error_page.htm page exposes the new_lan_ip variable or internal network configuration without requiring authentication.
Generated from the published advisory. Verify against your own configuration.
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 data3.0.0.4.382.50470384.4
Update Asuswrt-Merlin firmware to version 384.4 or later, and ASUS firmware to 3.0.0.4.382.50470 or later. If immediate patching is not possible, restrict access to the router's web interface from untrusted networks.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2018-8877 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-8877 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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