However, that's not quite front-running in the established sense.

That paper is about a side-effect based on the design of "Decentralized Exchanges" on Ethereum and similar systems. That's why people should always dive in the details of those blockchain solutions; not only you have implementation issues, but even design issues where the "solution" falls apart when game theory is accounted for all actors and interactions with the network.

Unfortunately, the complexity of such "decentralized solutions" makes it easy to miss a lot of issues. Even with audits that cost thousands of dollars per case, you still have several cases where serious vulnerabilities go unnoticed.

Here's a talk about this research that Philip Daian gave at Devcon 4:

https://slideslive.com/38911605/smart-contract-security-ince...

Probably my favourite talk from that conference.