This signature detectings exe file transmission over TFTP, and is not for any specific vulnerability.
It is uncommon that an exe file be transmitted by TFTP. When it happens, the user should check whether it is permitted. This could indicate possible worm activity.
Any unprotected Windows system may be affected.
Malicious program execution
Check whether it's permitted to download NC.EXE file to your PC over TFTP and use antivirus software to scan the system.