CVE-2020-1350 — Microsoft Windows DNS Server Remote Code Execution Vulnerability
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'.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Public exploit/PoC (github)+6
- EPSS 96.7% (30-day exploitation probability)+15
- Technical severity (critical)+10
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — portal.msrc.microsoft.com (NIST National Vulnerability Database)
CISA required action CISA
Apply updates per vendor instructions.
US federal deadline: May 3, 2022 — passed 1626 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Microsoft Windows Server, Microsoft Windows Server 2008, Microsoft Windows Server 2012…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (input validation), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Microsoft | Windows Server |
version 2008 for 32-bit Systems Service Pack 2version 2012 R2 (Core installation)version 2012 R2version 2012 (Core installation)version 2012version 2008 R2 for x64-based Systems Service Pack 1 (Core installation)version 2008 R2 for x64-based Systems Service Pack 1version 2008 for x64-based Systems Service Pack 2 (Core installation) and 6 moreversion 2008 for x64-based Systems Service Pack 2version 2008 for 32-bit Systems Service Pack 2 (Core installation)version 2016 (Core installation)version 2016version 2019 (Core installation)version 2019 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Microsoft | Windows Server 2008 | version r2-sp1versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Windows Server 2012 | version r2versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Windows Server 2016 | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Windows Server 2019 | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 10.0 | CVSS 3.1 | Critical | 3.9 | 6.0 | nvd@nist.gov via NIST National Vulnerability Database |
| 10.0 | CVSS 3.1 | Critical | 3.9 | 6.0 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 10.0 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 10.0 | CVSS 3.1 | Critical | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
| 10.0 | CVSS 2.0 | High | 10.0 | 10.0 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
- 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. ★ 280 Jul 14, 2020
- A denial-of-service proof-of-concept for CVE-2020-1350 ★ 238 Jul 15, 2020
- NSE scripts to detect CVE-2020-1350 SIGRED and CVE-2020-0796 SMBGHOST, CVE-2021-21972, proxyshell, CVE-2021-34473 ★ 162 Mar 11, 2020
- Denial of Service PoC for CVE-2020-1350 (SIGRed) ★ 18 Jul 16, 2020
- This Powershell Script is checking if your server is vulnerable for the CVE-2020-1350 Remote Code Execution flaw in the Windows DNS Service ★ 15 Jul 15, 2020
- CVE-2020-1350 Proof-of-Concept ★ 11 Jul 17, 2020
- Detection of attempts to exploit Microsoft Windows DNS server via CVE-2020-1350 (AKA SIGRed) ★ 9 Jul 15, 2020
- Fake exploit tool, designed to rickroll users attempting to actually exploit. ★ 7 Jul 14, 2020
- mr-r3b00t/CVE-2020-1350 ★ 4 Jul 14, 2020
- Scanner and Mitigator for CVE 2020-1350 ★ 2 Jul 18, 2020
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 96.72%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Hunt retroactively in logs from before Nov 3, 2021 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · microsoft/windows server
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · microsoft/windows server 2008, microsoft/windows server 2012, microsoft/windows server 2016, microsoft/windows server 20
- CVSS changed · 10.0
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- 2021
- Added to CISA KEV catalog
- 2020
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
5 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-97844 Role: DNS Server Information Disclosure Vulnerability 2d
- Medium CVE-2026-97841 Role: DNS Server Information Disclosure Vulnerability 2d
- Medium CVE-2026-97840 Role: DNS Server Information Disclosure Vulnerability 2d
- Medium CVE-2026-97839 Role: DNS Server Information Disclosure Vulnerability 2d
- Medium CVE-2026-97843 Role: DNS Server Information Disclosure Vulnerability 2d
- Medium CVE-2026-97842 Role: DNS Server Information Disclosure Vulnerability 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2020-1350 is "Microsoft Windows DNS Server Remote Code Execution Vulnerability", rated Critical. It affects Windows Server (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 10.0 describes technical severity. EPSS 96.72% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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