Nssm224 Privilege Escalation Updated _verified_ ⚡ Extended

You should assume that an attacker could have already replaced the binary.

: Ensuring that service definitions in HKLM\System\CurrentControlSet\Services cannot be modified by non-admin users.

Always enclose service paths containing spaces in quotation marks. When using NSSM, ensure both the path to nssm.exe and the application it references are properly wrapped: nssm224 privilege escalation updated

Given its simplicity and effectiveness, NSSM is widely integrated into third-party software installers. For instance, automation tools, streaming engines, and management suites often bundle NSSM to ensure their background processes run with SYSTEM-level integrity. However, this deep integration into the operating system’s service control mechanism has recently been identified as a double-edged sword.

Understanding NSSM224: A Deep Dive into the Windows Privilege Escalation Vulnerability You should assume that an attacker could have

Note: This walkthrough is for educational and authorized penetration testing purposes only. Step 1: Enumeration and Identification

Affecting Wowza Streaming Engine 4.5.0, this local privilege escalation arises because “improper file permissions granting full access to the Everyone group” allow authenticated users to replace the nssm_x64.exe binary. Once replaced, the malicious binary executes with LocalSystem privileges when the Wowza services restart. As one security bulletin notes, the binary “is accessible to the Everyone group, allowing authenticated users … to replace the nssm_x64.exe binary with malicious executables that will execute with LocalSystem privileges when the services restart”. When using NSSM, ensure both the path to nssm

A standard domain or local user replaces the legitimate nssm.exe or the wrapped application executable with a malicious payload (e.g., a reverse shell generated via MSFvenom). When the service restarts, the malicious payload executes with the privileges assigned to that service (usually SYSTEM ). 2. Registry Permission Flaws

: Organizations use the Wazuh blog guide to monitor for suspicious services created with NSSM . Manual Check for Unquoted Paths :

Get-WmiObject win32_service | Select-Object Name, State, PathName | Where-Object $_.PathName -like "*nssm*" Use code with caution. Step 2: Check Directory Permissions

Implement file integrity monitoring (FIM) on critical directories where NSSM is installed. Alerts on modifications to nssm.exe can provide early warning of an attempted privilege escalation. Solutions such as Microsoft Defender for Endpoint, Sysmon (Event ID 11 for file creation), or third‑party EDR tools can detect and block unauthorized file replacements.