F5d5230 4 4 Port Cable Dsl Gateway RouterHardware / appliance · Belkin

CVE-2002-1431

HIGH · 7.5 CVSS v2.0 Published 2003-04-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges 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
Belkin F5D5230-4 4-Port Cable/DSL Gateway Router 1.20.000 modifies the source IP address of internal packets to that of the router's external interface when forwarding a request from an internal host to an internal web server, which allows remote attackers to hide which host is being used to access the web server.

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

The Belkin F5D5230-4 router incorrectly performs Network Address Translation (NAT) on internal-to-internal traffic, replacing the original source IP address of internal hosts with the router's external interface IP when forwarding requests to internal web servers. This causes internal network traffic to appear as originating from the router's public IP, exposing internal network topology and allowing attackers to obscure their actual source IP when accessing internal resources.

MitigationReplace the obsolete Belkin router with a current, supported device that properly handles internal traffic without source IP modification. If replacement is not immediately feasible, isolate sensitive internal servers on a separate VLAN or implement internal firewall rules to log and monitor traffic origin.

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
F5d5230 4 4 Port Cable Dsl Gateway RouterHardware / appliance
Affected:= 1.20.000

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
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

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. Identify the router model
    Locate the physical device or check network inventory documentation to confirm the exact model number is Belkin F5D5230-4 4 Port Cable/DSL Gateway Router
    Affected if The device is a Belkin F5D5230-4 router
  2. Check the firmware version
    Access the router administration interface (typically via web browser at 192.168.1.1 or 192.168.2.1) and navigate to the status or firmware version page to determine the installed firmware version
    Affected if The firmware version is exactly 1.20.000
  3. Verify internal traffic behavior
    From an internal client host, use a web browser or curl to access a web server hosted on another internal host or the router itself. On the internal web server, examine the HTTP request source IP address (check access logs or use netcat/ss to observe incoming connections)
    Affected if The internal web server sees the router's external/public IP address instead of the internal client IP address as the source of the request

You are affected if you have a Belkin F5D5230-4 router running firmware version 1.20.000 and internal-to-internal web traffic appears to originate from the router's external IP rather than the actual internal client IP addresses.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace the obsolete Belkin router with a current, supported device that properly handles internal traffic without source IP modification. If replacement is not immediately feasible, isolate sensitive internal servers on a separate VLAN or implement internal firewall rules to log and monitor traffic origin.

Fix this in F5d5230 4 4 Port Cable Dsl Gateway Router Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2002-1431 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
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