---
id: "CVE-2020-1350"
kind: "vulnerability"
aliases: ["CVE-2020-1350"]
title: "Microsoft Windows: Microsoft Windows DNS Server Remote Code Execution Vulnerability"
severity: "critical"
cvss: 10.0
epss: 0.96721
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Microsoft Windows", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["active-directory", "dns-server", "exploited", "infrastructure", "windows", "windows-server"]
not_affected_if: ["no-windows-dns-server-role"]
published_at: "2020-07-14T23:15:13+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T21:57:34+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-1350", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2020-1350", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-1350", "first_seen_at": "2026-10-23T21:57:34+00:00"}]
---

# Microsoft Windows: Microsoft Windows DNS Server Remote Code Execution Vulnerability

Windows DNS Server mishandles certain requests, letting a remote attacker run code as the Local System account. The flaw is known as SIGRed and is listed by CISA as actively exploited.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft Windows affected ? fixed ?

## Fix

Apply the Microsoft update for CVE-2020-1350 per vendor instructions (CISA KEV action); the specific KB number is not in the sources.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-1350
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2020-1350
- 2026-10-23T21:57:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2020-1350

## From the sources

Microsoft Windows DNS Servers fail to properly handle requests, allowing an attacker to perform remote code execution in the context of the Local System Account. The vulnerability is also known under the moniker of SIGRed.

CISA required action: Apply updates per vendor instructions.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_