[xgk]

The possibility of flipping bits in DRAM in a Rowhammer like fashion, was known in the DRAM industry since at least the 1990s (sorry, no reference handy), and Rowhammer-like access was used in DRAM quality testing.

As silicon density increased, the issue became more urgent.

[defrost]

That matches my recollection- I started in broad STEM at university in the 1980s and as chip sizes were pushed smaller and denser there was always thought given to signal bleed | harmonics from too many lines too close together.

I suspect "observed in fabrication lab | not disclosed" dates back some years before the paper .. once observed there's always a path to exploitation - but why would anyone broadcast that?

By the time it was chit chat on IRC the general feeling was that some TLA has a working exploit. (obviously unpublished).