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Full vulnerability report · 2020
CVE-2020-1350High confidence

Microsoft Windows DNS Server Remote Code Execution Vulnerability

Microsoft · Windows

10.0CriticalCVSS 3.1
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2022-05-03 as the remediation due date.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SEVD-2021-285-05 · CSAF 2.0 · revision 1.0.0 · finalSchneider Electric CPCERTConext™ Advisor & Conext™ Control V2
3 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • Schneider Electric Conext™ Advisor 2 Cloud 2.02 and below
  • Schneider Electric Conext™ Advisor 2 Gateway 1.28.45 and below
  • Schneider Electric Conext™ Control V2 Gateway 2.6 and below
Summary
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'.
Remediation
Version Windows 10 of the Microsoft Windows includes a fix for this vulnerability and is available for download here: • https://www.microsoft.com/en-in/software-download/windows10 • Reboot is required
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2020-12226

CISA KEV mirrored by ENISA

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'.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 3 Nov 2021. Evidence sources: cisa_kev.
ENISA score
10.0 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2022-05-03 as the remediation due date.

Patch available
01

What, why and how

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.

What

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.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

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.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2021-11-03.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Input Validation → execute code or commands in the affected security context
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-20 ↗

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkUnauthenticatedRemote code executionCWE-20CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2020-12226Known-exploited evidence recorded

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'.

Official EUVD record
CERT-FR · French · CERTFR-2021-AVI-772Multiples vulnérabilités dans les produits Schneider

ve.org/CVERecord?id=CVE-2019-0859 Référence CVE CVE-2019-1040 https://www.cve.org/CVERecord?id=CVE-2019-1040 Référence CVE CVE-2019-11135 https://www.cve.org/CVERecord?id=CVE-2019-11135 Référence CVE CVE-2020-0601 https://www.cve.org/CVERecord?id=CVE-2020-0601 Référence CVE CVE-2020-0609 https://www.cve.org/CVERecord?id=CVE-2020-0609 Référence CVE CVE-2020-0610 https://www.cve.org/CVERecord?id=CVE-2020-0610 Référence CVE CVE-2020-0796 https://www.cve.org/CVERecord?id=CVE-2020-0796 Référence CVE CVE-2020-0938 https://www.cve.org/CVERecord?id=CVE-2020-0938 Référence CVE CVE-2020-1020 https://www.cve.org/CVERecord?id=CVE-2020-1020 Référence CVE CVE-2020-1350 https://www.cve.org/CVERecord?id=CVE-2020-1350 Référence CVE CVE-2020-13987 https://www.cve.org/CVERecord?id=CVE-2020-13987 Référence CVE CVE-2020-1472 https://www.cve.org/CVERecord?id=CVE-2020-1472 Référence CVE CVE-2020-17438 https://www.cve.org/CVERecord?id=CVE-2020-17438 Référence CVE CVE-2021-22800 https://www.cve.org/CVERecord?id=CVE-2021-22800 Référence CVE CVE-2021-22801 https://www.cve.org/CVERecord?id=CVE-2021-22801 Référence CVE CVE-2021-22802 https://www.cve.org/CVERecord?id=CVE-2021-22802 Référence CVE CVE-2021-22803 https://www.cve.org/CVERecord?id=CVE-2021-22803 Référence CVE CVE-2021-22804 https://www.cve.org/CVERecord?id=CVE

Official advisory
CERT-FR · French · CERTFR-2020-AVI-429Multiples vulnérabilités dans Microsoft Windows

.cve.org/CVERecord?id=CVE-2020-1085 Référence CVE CVE-2020-1249 https://www.cve.org/CVERecord?id=CVE-2020-1249 Référence CVE CVE-2020-1267 https://www.cve.org/CVERecord?id=CVE-2020-1267 Référence CVE CVE-2020-1330 https://www.cve.org/CVERecord?id=CVE-2020-1330 Référence CVE CVE-2020-1333 https://www.cve.org/CVERecord?id=CVE-2020-1333 Référence CVE CVE-2020-1336 https://www.cve.org/CVERecord?id=CVE-2020-1336 Référence CVE CVE-2020-1344 https://www.cve.org/CVERecord?id=CVE-2020-1344 Référence CVE CVE-2020-1346 https://www.cve.org/CVERecord?id=CVE-2020-1346 Référence CVE CVE-2020-1347 https://www.cve.org/CVERecord?id=CVE-2020-1347 Référence CVE CVE-2020-1350 https://www.cve.org/CVERecord?id=CVE-2020-1350 Référence CVE CVE-2020-1351 https://www.cve.org/CVERecord?id=CVE-2020-1351 Référence CVE CVE-2020-1352 https://www.cve.org/CVERecord?id=CVE-2020-1352 Référence CVE CVE-2020-1353 https://www.cve.org/CVERecord?id=CVE-2020-1353 Référence CVE CVE-2020-1354 https://www.cve.org/CVERecord?id=CVE-2020-1354 Référence CVE CVE-2020-1355 https://www.cve.org/CVERecord?id=CVE-2020-1355 Référence CVE CVE-2020-1356 https://www.cve.org/CVERecord?id=CVE-2020-1356 Référence CVE CVE-2020-1357 https://www.cve.org/CVERecord?id=CVE-2020-1357 Référence CVE CVE-2020-1358 https://www.cve.org/CVERecord?id=CVE-2020-1358 Ré

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Schneider Electric Conext™ Advisor 2 Cloud 2.02 and below; Schneider Electric Conext™ Advisor 2 Gateway 1.28.45 and below; Schneider Electric Conext™ Control V2 Gateway 2.6 and below
Fixed
Schneider Electric Microsoft Windows 10
Action
Version Windows 10 of the Microsoft Windows includes a fix for this vulnerability and is available for download here: • https://www.microsoft.com/en-in/software-download/windows10 • Reboot is required
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 14 Jul 2020 · Last source change 21 Oct 2025, 23:35 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-12226
Product sourceVendor CSAF · Schneider Electric CPCERT
Remediation sourceVendor CSAF · Schneider Electric CPCERT
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2020-12226↗Vendor CSAF · Schneider Electric CPCERT↗CISA KEV record↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2020-1350 · cve.blacktree.nl