The attacker stops and restarts the service (if they have SERVICE_START and SERVICE_STOP rights) or waits for a system reboot:
Under this key, NSSM defines values like Application , AppDirectory , and AppParameters .
Before dissecting the vulnerabilities, it is essential to understand what NSSM is and why version 2.24 is so pervasive. NSSM, short for Non-Sucking Service Manager, is a service helper program. It solves a persistent problem in Windows: many simple applications and scripts are not designed to run as system services. NSSM bridges that gap by acting as a wrapper. It starts any application or command line script as a Windows service, automatically restarts it if it fails, and provides service-specific environment variables and logging capabilities. Unlike Microsoft’s own srvany.exe , NSSM is more robust, easier to configure, and remains actively maintained. nssm-2.24 privilege escalation
– Never place service executables in user-writable paths (avoid ProgramData , Temp , Users folders). Use C:\Program Files or C:\Windows\System32 .
: Ensure that only administrators have "Write" or "Modify" permissions on the directory where nssm.exe is located and the Registry keys associated with the service. The attacker stops and restarts the service (if
Later versions of NSSM (2.24.1, 2.25, and above) introduced critical safeguards:
NSSM allows a standard user (without admin rights) to install a service, but here lies the critical catch: on Windows. You cannot simply run nssm install from a command prompt as a standard user and succeed. Or so the logic goes. It solves a persistent problem in Windows: many
The impact of successfully exploiting an NSSM privilege escalation is .
The security issues with NSSM-2.24 are not rooted in complex buffer overflows or advanced memory corruption. Instead, they arise from simpler, yet equally devastating, misconfigurations. Attackers are not exploiting code in NSSM itself—they are exploiting the Windows operating system interacts with the nssm.exe binary and the services it creates.