# CVE-2020-0646: Microsoft .NET Framework Remote Code Execution

> Remote attackers can execute arbitrary code by exploiting improper input validation in the Microsoft .NET Framework.

- **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:** Yes, since 3 Nov 2021 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jan 2020
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-4w3v-83v8-mg94

## What is CVE-2020-0646?

CVE-2020-0646 is a critical code injection vulnerability in Microsoft .Net Framework, published on 14 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A remote code execution vulnerability exists when the Microsoft .NET Framework fails to validate input properly, aka '.NET Framework Remote Code Execution Injection Vulnerability'.

Weakness: CWE-91 (XML Injection)

## Which versions are affected by CVE-2020-0646?

It affects 1 product.


Products: Microsoft .Net Framework.

## How do I fix CVE-2020-0646?

No fix has been published for CVE-2020-0646 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

## Is CVE-2020-0646 being exploited?

Yes. Attackers have exploited CVE-2020-0646 in the wild since at least 3 Nov 2021.

Public exploit code:

- SharePoint Workflows XOML Injection (metasploit)
- SharePoint Workflows - XOML Injection (Metasploit) (exploitdb)

## Other vulnerabilities in Microsoft .Net Framework

- [CVE-2017-8759](https://insights.sbomify.com/CVE-2017-8759/): Microsoft .NET Framework Remote Code Execution (high 7.8, exploited in the wild)
- [CVE-2015-1671](https://insights.sbomify.com/CVE-2015-1671/): Microsoft Windows Remote Code Execution (high 7.8, exploited in the wild)
- [CVE-2024-29059](https://insights.sbomify.com/CVE-2024-29059/): Microsoft .NET Framework Information Disclosure (high 7.5, exploited in the wild)
- [CVE-2014-4073](https://insights.sbomify.com/CVE-2014-4073/): Privilege escalation in n/a (critical 10.0)
- [CVE-2014-4121](https://insights.sbomify.com/CVE-2014-4121/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-0646 and fix it if it is affected.

What it is: CVE-2020-0646 is a critical code injection vulnerability in Microsoft .Net Framework, published on 14 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-0646 in the wild since at least 3 Nov 2021.

Affected product: Microsoft .Net Framework. 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-2020-0646/ (Markdown: https://insights.sbomify.com/CVE-2020-0646/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-0646
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-0646
- OSV: https://osv.dev/vulnerability/CVE-2020-0646

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-0646/
Summaries are generated and may contain mistakes; the official description above is the record.