CVE-2006-6265
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 · uneditedTeredo clients, when located behind a restricted NAT, allow remote attackers to establish an inbound connection without the guessing required to find a port mapping for a traditional restricted NAT client, by (1) using the client port number contained in the Teredo address or (2) following the bubble-to-open procedure.
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 confidenceTeredo clients behind restricted NATs contain a vulnerability where remote attackers can establish inbound connections without the port-guessing attack required for traditional restricted NAT clients. The attack exploits either (1) the client port number embedded in the Teredo address or (2) the bubble-to-open procedure used for NAT traversal, effectively bypassing the security boundary that restricted NATs normally provide.
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 dataall 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
- Adjacent
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:A/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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Check if Teredo is enabled on the systemRun `netsh interface teredo show state` on Windows systems to see the current Teredo configuration and status. Look for the 'State' field to determine if Teredo is enabled, disabled, or in an error state.Affected if Teredo is enabled and active (State shows 'Enabled' or 'Online')
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Identify the Teredo adapter presenceCheck network adapter list (ipconfig /all or Get-NetAdapter in PowerShell) for a Teredo Tunneling Pseudo-Interface or similar Teredo-named adapter that is present and enabled.Affected if A Teredo network adapter exists and is enabled
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Verify NAT environment configurationDetermine if the system is operating behind a NAT (Network Address Translation) by examining IP configuration or consulting with network administrators about the network topology.Affected if The system is behind a restricted NAT and Teredo is enabled
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Confirm Teredo is actually in useReview system network connections and active listeners to see if Teredo-originated traffic is being processed, or check logs for Teredo-related bubble or tunnel activity.Affected if Teredo traffic is being actively processed by the system while behind a restricted NAT
A system is affected if Microsoft Teredo is enabled and the host is operating behind a restricted NAT, allowing attackers to bypass the security boundary normally provided by restricted NAT configurations.
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 dataOrganizations should audit for Teredo usage in their environments and disable Teredo if not required, or implement network-level filtering to block unsolicited inbound Teredo bubbles at network boundaries.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2006-6265 — 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-2006-6265 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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