CVE-2023-41355
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 · uneditedChunghwa Telecom NOKIA G-040W-Q Firewall function has a vulnerability of input validation for ICMP redirect messages. An unauthenticated remote attacker can exploit this vulnerability by sending a crafted package to modify the network routing table, resulting in a denial of service or sensitive information leaking.
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 · moderate confidenceThe Nokia G-040W-Q firewall used by Chunghwa Telecom has a critical input validation flaw in its ICMP redirect message handling. An unauthenticated remote attacker can send specially crafted ICMP redirect packets to manipulate the device's routing table, causing traffic redirection for denial of service or interception of sensitive data.
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= g040wqr201207CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify the device modelLog into the device administrative interface or check the device label to confirm it is a Nokia G-040W-Q firewall used by Chunghwa Telecom.Affected if The device is not a Nokia G-040W-Q model, then this specific CVE does not apply.
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Check the firmware versionAccess the device firmware/version information page in the administrative interface or use the command line interface (e.g., 'show version' or 'firmware info') to retrieve the installed firmware version.Affected if The installed firmware version is exactly g040wqr201207, indicating it matches the affected version.
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Verify ICMP redirect handling is enabledCheck the device network configuration settings for ICMP redirect message acceptance. This may be found under advanced network settings, security settings, or routing configuration. Look for options such as 'Accept ICMP redirects', 'Enable ICMP redirect', or similar.Affected if ICMP redirect message acceptance is enabled or set to allow, making the device vulnerable to specially crafted redirect packets.
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Inspect the routing table for unexpected entriesAccess the device's routing table (typically via 'show ip route' or similar command in the CLI) and review all static and dynamically learned routes for any suspicious or unexpected gateway entries that may indicate manipulation via ICMP redirects.Affected if The routing table contains unfamiliar or suspicious routes, particularly default gateway changes or unexpected next-hop addresses that were not intentionally configured.
A user is affected if they are running a Nokia G-040W-Q firewall with firmware version g040wqr201207 that has ICMP redirect message acceptance enabled.
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 dataDisable acceptance of ICMP redirect messages on the affected device and implement strict input validation for ICMP traffic at network boundaries. If available, apply vendor firmware updates.
- Consultation4.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-41355 — 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-2023-41355 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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- 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
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