CISA KEV source record / CVE-2020-1350

Microsoft Windows DNS Server Remote Code Execution Vulnerability

Microsoft / Windows

Known exploitation catalogNot a Secureline discoveryNot a live alert

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.

CVE identifier: CVE-2020-1350
Added to KEV: Nov 3, 2021
CISA catalog dueDate: May 3, 2022

The dates above are catalog fields. The addition date does not establish when the vulnerability was discovered or first exploited. Confirm which requirements apply to your organisation separately.

Publisher's required action

Apply updates per vendor instructions.

This wording is attributed to the CISA snapshot. Verify current vendor guidance, affected versions and your deployment before applying changes.

Keep the signals separate.

Ransomware use, as reported by CISA: Unknown
CVSS severity: Not supplied by KEV
EPSS probability: Not available

No EPSS value was supplied for this record in the current snapshot. Unknown values are not treated as zero.

“Unknown” ransomware use is an unknown source field, not proof that ransomware activity has not occurred.

Source notes

Reference CISA's ED 20-03 (https://www.cisa.gov/news-events/directives/ed-20-03-mitigate-windows-dns-server-remote-code-execution-vulnerability-july-2020-patch-tuesday) for further guidance and requirements. Note: The due date for addressing this vulnerability aligns with the requirements outlined in ED 20-03. https://nvd.nist.gov/vuln/detail/CVE-2020-1350

Source & freshness

Catalog version 2026.11.06
Source updated: Nov 6, 2026, 7:44 PM UTC
Successfully checked: Nov 8, 2026, 12:22 AM UTC

CISA source snapshot ↗CVE record ↗EPSS methodology ↗

Automated source record, not an editorial advisory or an independent discovery. No affected or fixed version is inferred, and no organisation-specific risk rating is generated.