Buchanan tweeted he cracked something. It's been hinted that pirates have cracked widevine for Netflix already. Why is there half a dozen articles on it? Anyone can tweet claims, show some proof.
POC || gtfo
POC || gtfo
I think the guy is awesome and very likely he did what he claimed, but do get annoyed about low effort Twitter journalism. Prove it or don't write it. It's very simple.
EDIT: If reversing this DLL/so is illegal, how I am supposed to be able to test for a potential security vulnerability? Not that I can do this, just wondering...
You aren't. There were some amendments made to DMCA recently that added a few more narrow provisions (mainly repairing tractors and such), but I don't think reverse engineering closed libraries was one of them. In particular, things close to DRM were not granted. For example, request for exemptions for tinkering with HDCP or optical drives were denied.