[nomel]

> Unfortunately, this elegant, straightforward distinction didn't hold up over time. :-(

I think it was more that it was never true, rather than not holding up in time. ;)

The earliest I can find is a vulnerability in Netscape 3.0 (1996), not found until four years later:

https://www.openwall.com/articles/JPEG-COM-Marker-Vulnerabil...

[thrashh]

You just need a buffer overflow in a file format parser.

Thus the distinction has never existed. There has never been such thing as a “safe” format.