I respectfully disagree. I have a embedded multi-threaded 'C' program running in over 11k+ retail stores in the USA right now. It's been handling multiple client requests to a Sqlite DB since 2007 without any issues. This product has made my company a lot of revenue. The secret to using threads is all in the design. Don't share resources between threads (I only had one shared resource for 50+ threads guarded by a semaphore).

Cheers.

That is a decent anecdote. Well, with respect, allow me to revise and qualify my read of @baggy_trough's comment:

It's perfectly fine to continue using an existing C codebase for a program, not exposed to the public internet, that's maintained by a focused group of maintainers. But on the other side of this spectrum, for large exposed projects like OpenSSL, Chromium, or even Linux, C/C++ has become risky.

Has anyone read any article on how this vulnerability is spreading via SMB V1? With the Robert Morris worm/I Love you/Conficker we knew exactly how the worm spread.

From a programmers perspective, what is this thing doing? Is there an nmap filter to find vulnerable clients yet? If not, how do I create one. I'd like to be pro-active with my current customers concerns.

Thanks,

It uses a buffer overflow in the SMBv1 message block to.

Effectively to filter it you need to block all SMBv1 packets. Which you should do already because the modern SMB is v3

Let alone you shouldn't be listening for AD management commands from the wide internet.