Rule Document 1:55802

Report a false positive

Rule Category

OS-WINDOWS -- Snort has detected traffic targeting vulnerabilities in a Windows-based operating system. This does not include browser traffic or other software on the OS, but attacks against the OS itself. (such as?)

Alert Message

OS-WINDOWS Microsoft Windows NetrServerReqChallenge RPC transport sign and seal disabling attempt

Rule Explanation

This rule looks for specially crafted NetrServerAuthenticate3 requests sent to Windows MS-NRPC servers that are intended to gain unauthenticated access to a Domain Controller.

What To Look For

This rule fires on attempts to exploit an authentication bypass vulnerability in the Microsoft Netlogon Remote Protocol.

Known Usage

Attacks/Scans seen in the wild

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

Rule Groups

No rule groups

CVE

CVE-2020-1472 CVE-2025-33070

Additional Links

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1472
support.microsoft.com/en-us/help/4557222/how-to-manage-the-changes-in-netlogon-secure-channel-connections-assoc
msrc.microsoft.com/update-guide/vulnerability/CVE-2025-33070

Rule Vulnerability

Authentication Bypass

An Authentication Bypass occurs when there is a way to avoid providing user credentials to a system before performing restricted operations on said system.

CVE Additional Information

This product uses data from the NVD API but is not endorsed or certified by the NVD.
CVE-2020-1472
 Loading description
CVE-2025-33070
 Loading description