Those 1,700 are easy to find though, just need to dig a bunch of domain names and you'll find plenty vulnerable ones that you can spoof.
Yahoo Mail has a market share on the order of 3%. So a black hat could then target a decent chunk of users with @yahoo addresses specifically.
Has anyone heard of this being exploited in the wild? Would be interesting to find out whether there are some reputable domains among the 1.7k vulnerable ones.
remember when yahoo mail was the first one to implement DKIM validation and then all mailing list owners added a footer telling their subscribers not to use yahoo mail because it was broken, instead of calling their mailing list providers to upload a key? yeah nobody remembers, but yahoo probably do. i doubt they will err on the side of security again.
Yahoo Mail has a market share on the order of 3%. So a black hat could then target a decent chunk of users with @yahoo addresses specifically.
Has anyone heard of this being exploited in the wild? Would be interesting to find out whether there are some reputable domains among the 1.7k vulnerable ones.