CVE-2002-0109
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 · uneditedLinksys EtherFast BEFN2PS4, BEFSR41, and BEFSR81 Routers, and possibly other products, allow remote attackers to gain sensitive information and cause a denial of service via an SNMP query for the default community string "public," which causes the router to change its configuration and send SNMP trap information back to the system that initiated the query.
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 remote attackers to query Linksys routers (BEFN2PS4, BEFSR41, BEFSR81) using the default SNMP community string 'public', causing the router to leak sensitive configuration information, modify its settings, and send SNMP traps back to the attacker, resulting in information disclosure and potential denial of service.
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= 0.0= 0.0all versionsCVSS 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
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:N/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 the router modelCheck the label on the router or log into the router's web administration interface to confirm the exact model number (BEFN2PS4, BEFSR41, or BEFSR81)Affected if The router is one of these three Linksys models and SNMP is enabled
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Verify SNMP is enabledLog into the router's web admin panel and navigate to the SNMP or Administration settings to confirm whether the SNMP service is turned onAffected if SNMP is enabled on the router
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Check the configured SNMP community stringsIn the router's SNMP configuration page, inspect the read and write community string settingsAffected if The community string is set to the default value 'public' (case-sensitive)
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Determine SNMP accessibilityFrom an untrusted network or external IP, attempt an SNMP query (snmpwalk) to the router's public IP using community string 'public'Affected if The router responds to SNMP queries from untrusted networks with the default community string
A user is affected if they own a BEFN2PS4, BEFSR41, or BEFSR81 router with SNMP enabled and the default community string 'public' configured, especially if the router's SNMP port is accessible from untrusted networks.
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 dataChange or disable the default SNMP community string 'public', disable SNMP if unused, and restrict SNMP access to trusted management IPs via firewall rules.
- Consultation2.0 h
- Implementation1.0 h
- Testing1.0 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 $1,456.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2002-0109 — 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-2002-0109 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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