How severe is CVE-2020-1350?

CVE-2020-1350 has a CVSS 3.1 base score of 10 (CRITICAL). EPSS estimates a 96.7% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

SIGRed (CVE-2020-1350): Microsoft Windows DNS Server Remote Code

Q: What is SIGRed?

SIGRed is the common name for CVE-2020-1350. Check Point Research published SIGRed on July 14, 2020. It is a wormable flaw in Windows DNS Server that a malicious DNS response can trigger. Microsoft lists Windows Server 2008 SP2 through Windows Server 2019, plus the Server Core releases of versions 1903, 1909 and 2004, as affected.

CISA Known Exploited Vulnerabilities

Microsoft Windows DNS Server Remote Code Execution Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2022-05-03

Required action
Apply updates per vendor instructions.

CISA 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

Also Known as SIGRed

Check Point Research published SIGRed on July 14, 2020. It is a wormable flaw in Windows DNS Server that a malicious DNS response can trigger. Microsoft lists Windows Server 2008 SP2 through Windows Server 2019, plus the Server Core releases of versions 1903, 1909 and 2004, as affected.

Name sources

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'.

Severity

CVSS 3.1 · CISA10 CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impacttotal

Exploitation Context

as of October 13, 2026

All KEV statistics→

CISA added CVE-2020-1350 to the KEV catalog 477 days after its CVE record was published.
It is one of 390 Microsoft entries in the CISA KEV catalog, and one of 83 added in 2021.
Its current EPSS score (96.7%) is higher than that of 81% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
Microsoft	Microsoft Windows Server	2019 2019 (Core installation) 2016 2016 (Core installation) 2008 for 32-bit Systems Service Pack 2 2008 for 32-bit Systems Service Pack 2 (Core installation) 2008 for x64-based Systems Service Pack 2 2008 for x64-based Systems Service Pack 2 (Core installation) 2008 R2 for x64-based Systems Service Pack 1 2008 R2 for x64-based Systems Service Pack 1 (Core installation) 2012 2012 (Core installation) 2012 R2 2012 R2 (Core installation)
Microsoft	Microsoft Windows Server, version 1909 (Server Core installation)	unspecified
Microsoft	Microsoft Windows Server, version 1903 (Server Core installation)	unspecified
Microsoft	Microsoft Windows Server, version 2004 (Server Core installation)	unspecified

References

2 Links

Other references

Record Details

Published

2020-07-14

Last updated

2025-10-21

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.