# CVE-2020-1350: Microsoft Windows DNS Server Remote Code Execution

> Remote attackers can execute arbitrary code on Windows DNS servers by sending specially crafted requests, requiring immediate patching.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 Jul 2020
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-hcmx-443w-mr76

## What is CVE-2020-1350?

CVE-2020-1350 is a critical memory corruption vulnerability in Microsoft Windows Server 2008, published on 14 Jul 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 in Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-1350?

It affects 4 products.


Products: Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019.

## How do I fix CVE-2020-1350?

No fix has been published for CVE-2020-1350 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

## Is CVE-2020-1350 being exploited?

Yes. Attackers have exploited CVE-2020-1350 in the wild since at least 3 Nov 2021.

Public exploit code:

- HoneyPoC: Proof-of-Concept (PoC) script to exploit SIGRed (CVE-2020-1350). Achieves Domain Admin on Domain Controllers running Windows Server 2000 up to Windows Server 2019. (github_poc): https://github.com/ZephrFish/CVE-2020-1350_HoneyPoC
- A denial-of-service proof-of-concept for CVE-2020-1350 (github_poc): https://github.com/maxpl0it/CVE-2020-1350-DoS
- NSE scripts to detect CVE-2020-1350 SIGRED and CVE-2020-0796 SMBGHOST, CVE-2021-21972, proxyshell, CVE-2021-34473 (github_poc): https://github.com/psc4re/NSE-scripts
- Denial of Service PoC for CVE-2020-1350 (SIGRed) (github_poc): https://github.com/captainGeech42/CVE-2020-1350
- This Powershell Script is checking if your server is vulnerable for the CVE-2020-1350 Remote Code Execution flaw in the Windows DNS Service (github_poc): https://github.com/T13nn3s/CVE-2020-1350
- CVE-2020-1350 Proof-of-Concept (github_poc): https://github.com/connormcgarr/CVE-2020-1350

## Other vulnerabilities in Microsoft Windows Server 2008

- [CVE-2020-1040](https://insights.sbomify.com/CVE-2020-1040/): Microsoft Hyper-V RemoteFX vGPU Remote Code Execution (critical 9.0, exploited in the wild)
- [CVE-2011-1966](https://insights.sbomify.com/CVE-2011-1966/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-0239](https://insights.sbomify.com/CVE-2010-0239/): Memory corruption in n/a (critical 10.0)
- [CVE-2010-0240](https://insights.sbomify.com/CVE-2010-0240/): Code injection in n/a (critical 10.0)
- [CVE-2010-0241](https://insights.sbomify.com/CVE-2010-0241/): Code injection in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1350 and fix it if it is affected.

What it is: CVE-2020-1350 is a critical memory corruption vulnerability in Microsoft Windows Server 2008, published on 14 Jul 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-1350 in the wild since at least 3 Nov 2021.

Affected product: Microsoft Windows Server 2008. 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-2020-1350/ (Markdown: https://insights.sbomify.com/CVE-2020-1350/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1350
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1350
- OSV: https://osv.dev/vulnerability/CVE-2020-1350

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1350/
Summaries are generated and may contain mistakes; the official description above is the record.