# CVE-2020-9044: Metasys Improper Restriction of XML External Entity Reference

> An XXE vulnerability in Johnson Controls Metasys web services allows attackers to cause denial of service or read server files.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 10 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-gfgf-64cp-gxh7

## What is CVE-2020-9044?

CVE-2020-9044 is a high-severity vulnerability in Johnson Controls Metasys Application and Data Server (ADS, ADS-Lite), published on 10 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

XXE vulnerability exists in the Metasys family of product Web Services which has the potential to facilitate DoS attacks or harvesting of ASCII server files. This affects Johnson Controls' Metasys Application and Data Server (ADS, ADS-Lite) versions 10.1 and prior; Metasys Extended Application and Data Server (ADX) versions 10.1 and prior; Metasys Open Data Server (ODS) versions 10.1 and prior; Metasys Open Application Server (OAS) version 10.1; Metasys Network Automation Engine (NAE55 only) versions 9.0.1, 9.0.2, 9.0.3, 9.0.5, 9.0.6; Metasys Network Integration Engine (NIE55/NIE59) versions 9.0.1, 9.0.2, 9.0.3, 9.0.5, 9.0.6; Metasys NAE85 and NIE85 versions 10.1 and prior; Metasys LonWorks Control Server (LCS) versions 10.1 and prior; Metasys System Configuration Tool (SCT) versions 13.2 and prior; Metasys Smoke Control Network Automation Engine (NAE55, UL 864 UUKL/ORD-C100-13 UUKLC 10th Edition Listed) version 8.1.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2020-9044?

It affects 13 products.


Products: Johnsoncontrols Metasys Application and Data Server, Johnsoncontrols Metasys Extended Application and Data Server, Johnsoncontrols Metasys Lonworks Control Server, Johnsoncontrols Metasys Open Application Server, Johnsoncontrols Metasys Open Data Server, Johnsoncontrols Metasys System Configuration Tool, Johnsoncontrols Nae55 Firmware, Johnsoncontrols Nae85 Firmware, Johnsoncontrols Nie55 Firmware, Johnsoncontrols Nie59 Firmware, Johnsoncontrols Nie85 Firmware, Johnsoncontrols Ord-C100-13 Uuklc Firmware, Johnsoncontrols Ul 864 Uukl Firmware.

## How do I fix CVE-2020-9044?

No fix has been published for CVE-2020-9044 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-9044 being exploited?

There is no known exploitation of CVE-2020-9044 in the wild and no public exploit code.

## Other vulnerabilities in Johnson Controls Metasys Application and Data Server (ADS, ADS-Lite)

- [CVE-2021-36207](https://insights.sbomify.com/CVE-2021-36207/): Metasys privilege management (high 8.8)
- [CVE-2022-21937](https://insights.sbomify.com/CVE-2022-21937/): Metasys CSS (high 8.7)
- [CVE-2021-36202](https://insights.sbomify.com/CVE-2021-36202/): Metasys UI (high 8.4)
- [CVE-2022-21938](https://insights.sbomify.com/CVE-2022-21938/): Metasys MUI Graphics XSS (high 8.1)
- [CVE-2021-36205](https://insights.sbomify.com/CVE-2021-36205/): Metasys session token (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-9044 and fix it if it is affected.

What it is: CVE-2020-9044 is a high-severity vulnerability in Johnson Controls Metasys Application and Data Server (ADS, ADS-Lite), published on 10 Mar 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-2020-9044 in the wild and no public exploit code.

Affected product: Johnson Controls Metasys Application and Data Server (ADS, ADS-Lite). 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-2020-9044/ (Markdown: https://insights.sbomify.com/CVE-2020-9044/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-9044
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-9044
- OSV: https://osv.dev/vulnerability/CVE-2020-9044

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-9044/
Summaries are generated and may contain mistakes; the official description above is the record.