That's a non-point. There's nothing intrinsic about higher level language that prevents security holes. There are plenty of low-level languages that are immune to buffer overflows—Ada, Rust, D† (to an extent), Oberon†, Cyclone....

D and Ada have real and important software written in them, Rust has hype, Oberon is still actively developed, Cyclone influenced new languages (particularly Rust).

† Garbage collected by default