Linksys Wrt54g Router FirmwareApplication · Cisco
CVE-2011-4499
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 · uneditedThe UPnP IGD implementation in the Broadcom UPnP stack on the Cisco Linksys WRT54G with firmware before 4.30.5, WRT54GS v1 through v3 with firmware before 4.71.1, and WRT54GS v4 with firmware before 1.06.1 allows remote attackers to establish arbitrary port mappings by sending a UPnP AddPortMapping action in a SOAP request to the WAN interface, related to an "external forwarding" vulnerability.
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 Broadcom UPnP stack in Cisco Linksys WRT54G and WRT54GS routers contains a vulnerability where the UPnP IGD (Internet Gateway Device) implementation allows remote attackers on the WAN interface to add arbitrary port mappings via the AddPortMapping SOAP action. This external forwarding vulnerability enables an attacker to create inbound port forwards on the router, potentially exposing internal network devices to the internet and bypassing firewall 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
Linksys Wrt54g Router FirmwareApplication
<= 4.20.8= 3.03.9= 4.20.7
Linksys Wrt54gs Router FirmwareApplication
<= 4.70.6= 2.09.1<= 1.06all versions= 2.2= 1.0= 2.0= 3.0= 4.0CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify router modelLog into the router web interface or check the device label to confirm the model is WRT54G or WRT54GSAffected if Router is not a WRT54G or WRT54GS variant
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Check firmware versionAccess the router administration page (typically http://192.168.1.1), navigate to the Administration or Status section, and record the firmware version displayedAffected if Firmware version matches <= 4.20.8, 3.03.9, or 4.20.7 for WRT54G; or <= 4.70.6, 2.09.1, or <= 1.06 for WRT54GS; or is 2.2 for Linksys Wrt54g; or is 1.0, 2.0, 3.0, or 4.0 for Linksys Wrt54gs; or any version for Linksys Wrt54g (all versions affected)
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Verify UPnP is enabledIn the router web interface, locate the UPnP settings (usually under Administration or Advanced Settings) and confirm the UPnP enable option is checked or set to enabledAffected if UPnP is currently enabled on the router
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Confirm WAN-side UPnP accessibilityFrom an external network (not behind the router), attempt to access the UPnP service port (typically port 1900 UDP or HTTP port 49152+) on the router's public WAN IP address using a UPnP discovery tool or simple port probeAffected if UPnP service is reachable from the WAN/internet side
The router is affected if it is a WRT54G or WRT54GS model running an affected firmware version AND UPnP is enabled AND the UPnP service is exposed to the WAN interface, allowing remote attackers to add arbitrary port mappings.
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 dataUpdate router firmware to the specified versions (4.30.5 for WRT54G, 1.06.1 for WRT54GS v4, 4.71.1 for WRT54GS v1-v3). If updates are unavailable, disable UPnP entirely on the WAN interface or block UPnP/soap traffic at the network boundary.
Fix this in Linksys Wrt54g Router Firmware
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-4499 — 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-2011-4499 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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