Actively exploitedKnown ransomware use

CVE-2020-1472 Microsoft Netlogon Privilege Escalation Vulnerability

Microsoft's Netlogon Remote Protocol (MS-NRPC) contains a privilege escalation vulnerability when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller. An attacker who successfully exploits the vulnerability could run a specially crafted application on a device on the network. The vulnerability is also known under the moniker of Zerologon.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 3 Nov 2021.
  • CISA lists it as known to be used in ransomware campaigns.
  • Rated Medium severity (CVSS 5.5, scored by Vendor).
  • Named in Cybergen threat actor reporting: LockBit, Rhysida.
  • It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

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.

Affected Versions

ProductVersions
Microsoft Windows Server version 200410.0.0 to before publication
Microsoft Windows Server 201910.0.0 to before publication
Microsoft Windows Server 2019 (Server Core installation)10.0.0 to before publication
Microsoft Windows Server, version 1909 (Server Core installation)10.0.0 to before publication
Microsoft Windows Server, version 1903 (Server Core installation)10.0.0 to before publication
Microsoft Windows Server 201610.0.0 to before publication

From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for Microsoft Netlogon. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply updates per vendor instructions.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Not Sure If You Are Exposed?

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