# CVE-2017-5243: Weak cryptography in Nexpose hardware appliance

> Default SSH settings allow weak algorithms, enabling MITM and decryption attacks on Nexpose hardware appliances.

- **Severity:** High 8.5 (`CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Jun 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-p52h-rp33-x9gq

## What is CVE-2017-5243?

CVE-2017-5243 is a high-severity vulnerability in Rapid7 Nexpose hardware appliance, published on 6 Jun 2017. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The default SSH configuration in Rapid7 Nexpose hardware appliances shipped before June 2017 does not specify desired algorithms for key exchange and other important functions. As a result, it falls back to allowing ALL algorithms supported by the relevant version of OpenSSH and makes the installations vulnerable to a range of MITM, downgrade, and decryption attacks.

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2017-5243?

It affects 1 product.


Products: Rapid7 Nexpose.

## How do I fix CVE-2017-5243?

No fix has been published for CVE-2017-5243 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-5243 being exploited?

There is no known exploitation of CVE-2017-5243 in the wild and no public exploit code.

## Other vulnerabilities in Rapid7 Nexpose hardware appliance

- [CVE-2017-5264](https://insights.sbomify.com/CVE-2017-5264/): Cross-site request forgery in Nexpose (high 8.8)
- [CVE-2019-5638](https://insights.sbomify.com/CVE-2019-5638/): Rapid7 Nexpose Insufficient Session Management (high 8.7)
- [CVE-2017-5232](https://insights.sbomify.com/CVE-2017-5232/): Other in Nexpose (high 7.8)
- [CVE-2017-5230](https://insights.sbomify.com/CVE-2017-5230/): Hardcoded credentials in Nexpose (high 7.2)
- [CVE-2020-7382](https://insights.sbomify.com/CVE-2020-7382/): Unquoted Path in Rapid7 Nexpose Installer (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-5243 and fix it if it is affected.

What it is: CVE-2017-5243 is a high-severity vulnerability in Rapid7 Nexpose hardware appliance, published on 6 Jun 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2017-5243 in the wild and no public exploit code.

Affected product: Rapid7 Nexpose hardware appliance. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2017-5243/ (Markdown: https://insights.sbomify.com/CVE-2017-5243/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-5243
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-5243
- OSV: https://osv.dev/vulnerability/CVE-2017-5243

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-5243/
Summaries are generated and may contain mistakes; the official description above is the record.