I agree with the gist of your comment but I think it's a bit harsh to say that using C for curl was an error. If I can trust wikipedia the original release of the library was in 1997, at the time it was a perfectly reasonable choice IMO.
I doubt the library would have reached its current adoption levels if it had been written in any other language (and I presume an other C library would've taken its place).
You're speaking past each other. You're talking about "blame" in a moralistic sense, but the other posters just mean simple causation -- "would this fault have occurred if a safer language was used?"
The former sense would be useful... if you want to sue someone or something I guess? But the latter is more useful in real life, so that's what we're discussing
They are absolutely the fault of the language, given other languages would have made these bugs impossible.
Errare humanum est is hardly a new concept, blaming humans for not being computers is inane, and in fact qualifies for in errare perseverare diabolicum as out of misplaced pride you persevere in the core original error of using C.