A perspective from the Bitcoin Cash and Bitcoin Unlimited developer who discovered CVE-2018–17144
Six hundred microseconds. That is about the time that Matt Corallo wanted to shave off of block validation with his pull request in 2016 to Bitcoin Core. 600µs is a lot less than what is saved with more efficient block propagation, like XThin, Compact Blocks, or now Graphene over typical links, especially those that are of similar low-end quality in network speed like Raspberry Pis are in compute speed.
An optimization that was not in the focus by Core until XThin from Bitcoin Unlimited came onto the scene and kicked the Core team into gear on this issue. Furthermore, 600 microseconds is an order of magnitude or more below the variance between node validation speeds from a Raspberry Pi to a more high-end miner node and thus wholly in the range that the network already deals with. This 600 microsecond optimization now resulted in CVE-2018–17144.
Certainly the most catastrophic bug in recent years, and certainly one of the most catastrophic bugs in Bitcoin ever. This bug was initially suspected to potentially cause inflation, was reported because it led to reliable crashes and confirmed by closer analysis… to be actually allowing inflation! I have consistently and repeatedly criticized hubris and arrogance in the most prominent Core developers, and done so since 2013, when the bullshitting around the 1MB block size limit started.
Here we have an optimization that talks about avoiding “duplicate” validation like validation is nothing to worry about, an afterthought in Bitcoin almost.