# CVE-2020-6959: Deserialization in Honeywell Maxpro VMS & NVR

> Remote attackers can achieve code execution via unsafe deserialization in Honeywell MAXPRO VMS and NVR without authentication.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Jan 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3478-j759-vphx

## What is CVE-2020-6959?

CVE-2020-6959 is a critical unsafe deserialization vulnerability in Honeywell Maxpro VMS & NVR, published on 22 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The following versions of MAXPRO VMS and NVR, MAXPRO VMS:HNMSWVMS prior to Version VMS560 Build 595 T2-Patch, HNMSWVMSLT prior to Version VMS560 Build 595 T2-Patch, MAXPRO NVR: MAXPRO NVR XE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR SE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR PE prior to Version NVR 5.6 Build 595 T2-Patch, and MPNVRSWXX prior to Version NVR 5.6 Build 595 T2-Patch are vulnerable to an unsafe deserialization of untrusted data. An attacker may be able to remotely modify deserialized data without authentication using a specially crafted web request, resulting in remote code execution.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2020-6959?

It affects 6 products.


Products: Honeywell Hnmswvms Firmware, Honeywell Hnmswvmslt Firmware, Honeywell Maxpro Nvr Pe Firmware, Honeywell Maxpro Nvr Se Firmware, Honeywell Maxpro Nvr Xe Firmware, Honeywell Mpnvrswxx Firmware.

## How do I fix CVE-2020-6959?

No fix has been published for CVE-2020-6959 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-6959 being exploited?

There is no known exploitation of CVE-2020-6959 in the wild and no public exploit code.

## Other vulnerabilities in Honeywell Maxpro VMS & NVR

- [CVE-2020-6960](https://insights.sbomify.com/CVE-2020-6960/): SQL injection in Honeywell Maxpro VMS & NVR (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-6959 and fix it if it is affected.

What it is: CVE-2020-6959 is a critical unsafe deserialization vulnerability in Honeywell Maxpro VMS & NVR, published on 22 Jan 2020. 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-2020-6959 in the wild and no public exploit code.

Affected product: Honeywell Maxpro VMS & NVR. 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-2020-6959/ (Markdown: https://insights.sbomify.com/CVE-2020-6959/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-6959
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-6959
- OSV: https://osv.dev/vulnerability/CVE-2020-6959

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-6959/
Summaries are generated and may contain mistakes; the official description above is the record.