# CVE-2025-37730: Logstash Improper Certificate Validation in TCP output

> Attackers can intercept Logstash TCP output traffic via man-in-the-middle attacks when full SSL verification is configured but hostname checks are skipped.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 May 2025
- **Updated:** 6 May 2025
- **Also known as:** BIT-logstash-2025-37730, GHSA-qrf7-ph5v-mj2v

## What is CVE-2025-37730?

CVE-2025-37730 is a medium-severity vulnerability in Elastic Logstash, published on 6 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper certificate validation in Logstash's TCP output could lead to a man-in-the-middle (MitM) attack in “client” mode, as hostname verification in TCP output was not being performed when the ssl_verification_mode => full was set.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2025-37730?

1 open source package ship an affected version, including logstash.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `logstash` | Bitnami | From 8.0.0 | 8.18.1, 9.0.1 |

## How do I fix CVE-2025-37730?

Upgrade logstash to a fixed version for your release line: 8.18.1 or 9.0.1.

## Is CVE-2025-37730 being exploited?

There is no known exploitation of CVE-2025-37730 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-37730 and fix it if it is affected.

What it is: CVE-2025-37730 is a medium-severity vulnerability in Elastic Logstash, published on 6 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-37730 in the wild and no public exploit code.

Affected packages and fixed versions:
- logstash (Bitnami): affected from 8.0.0; fixed in 8.18.1, 9.0.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-37730/ (Markdown: https://insights.sbomify.com/CVE-2025-37730/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37730
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37730
- OSV: https://osv.dev/vulnerability/CVE-2025-37730

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37730/
Summaries are generated and may contain mistakes; the official description above is the record.