There is a human factor at work here. Rationally speaking, Herb is right 98% reduction is sufficient. But when the CTO's head is on the line, they won't listen and switch to Rust.
Infrastructure network code that runs on millions of servers worldwide is a completely different story. Being able to send a sequence of bytes that unlocks funny side-effects of a network service can be weaponised on a mass scale.
But I agree it depends heavily on exactly what application are we talking about. Is it running on server? Definitely needs to be security conscious. Is it a library that might at some point be used by an application running on a server? Needs to be more hardened than a nuclear bunker.
That software is almost certainly running on a network-connected machine though and likely has email access etc.. A spear-phising attack with a CAD file that contains an RCE exploit would be an excellent way to compromise that user and machine leading to attacks like industrial espionage, ransomwear, etc...
I'm betting here they don't; if they have security breaches it's due to '1q2w3e' being the password to their world-accessible PHP admin panel, and not because of C++ code.
Also that number is greatly exaggerated. It's simply not true anymore, check the CVE website if you don't believe me.
Another way of thinking about this, why are all of the browser teams who have some of the best C++ developers in the world and significant resources adopting memory-safe languages? Nobody at that level is doing that because it’s cool, so there might be something to be learned from their reasoning.
They aren't. Even Mozilla abandonded their Rust-in-Firefox project.