My impression: For years it was common practice that when CAs messed something up it would cause some complains, but no real consequences. The large CAs thought they were "too big to fail". They thought it would just go on like that. They (and many others in the industry) didn't believe that Google was serious when they threatened with browser removal. When they realized Google was serious it was too late to change their course.

It also probably helped that the CA business wasn't Symantec's bread-and-butter.

Corporate leadership at the board room level is often resistant to the idea that oversight is their job, even though it is literally their only job. (Insert "You Had One Job" meme image). In many cases these people are paid (especially on a per hour basis) more than anybody else in the entire organisation, they ought to be working _very hard_ to deserve this money, and at most corporates they do little or nothing.

Did Symantec's shareholders get the board responsible for this... replaced? Did they at least get a big cut in their wages given that they're apparently no good at their jobs? Nope.

The Web PKI in my not at all humble opinion is doing a better job of handling this problem today than, for example, many actual bona fide regulators. When Symantec kept trying to offer up little bits and pieces (e.g. let's wind up this lucrative Korean partnership programme we've secretly been running for years that had no effective oversight...) they were told it wasn't enough.

In the end this distrust that you're seeing now was mandatory but it was not intended as a "death sentence" for the Symantec CA function pe se. Symantec were told to go find somebody whose leadership we could trust, and let the trustworthy outfit physically run the CA (with Symantec's brands) while Symantec got their shit together and tried again in a year or two. In the process of negotiating such a deal with DigiCert Symantec instead sold their entire CA business to them, which everybody seems to have (in some cases grudgingly) accepted is a good enough outcome.

DigiCert did a better than might be expected job of this from a technical point of view, and I hope that it works for them commercially as a result.

[Edited for clarity]

I've wondered the same. Certificate trust was absolutely crucial to their business. The only thing I can think is that the leadership was oblivious to this. Maybe they didn't understand how certificates work.

Sell more certificates, make more money. Anything which gets in the way of making more money (like security) should be reduced or eliminated, with the right touch you can get bonuses / promotions for meeting fiscal goals and leave your successor to deal with the aftermath.

They might understand how certificates work but that doesn’t mean they know how to set up an organization with the right incentives to do it correctly.

Interestingly, I looked up the symantec CEO. He was previously the ceo of Blue Coat. Blue Coat is a maker of man in the middle proxy appliances for businesses to spy on their employees. They controversially got root certificate authority. Which could of course be used to mitm SSL sites (which they promised and crossed their heart they would never do).

https://www.theregister.co.uk/2016/05/27/blue_coat_ca_certs/

Symantec told us that there was a clear separation between the Blue Coat interception business and the CA business. Now, whether we should believe that having distrusted Symantec is a reasonable question, but of course distrusting the Symantec CA function also makes the question rather academic.

For users with Certificate Transparency checking (basically, Chrome) any dubious MITM certificates would have to be logged to show up as trusted public certificates. So there would not only be a smoking gun in the sense of the MITM cert being sent to all browsers that connected, it would be permanently preserved.

In addition Mozilla has an ongoing programme of trying to discover all the intermediate CAs that actually exist, partly because this occasions them to find various intermediates that probably _shouldn't_ exist and get them blacklisted. So this means if a intermediate exists and then you say you didn't realise it was being abused, you have the problem of explaining why you didn't report that it exists. If you say it's because you didn't know, it makes things worse - like if you say you didn't tell the IRS about the money because you got it when committing an armed robbery you weren't previously in the frame for - because that means your CA root was used to sign things you don't have a record of, and so obviously we can't trust your root any more...

Didn't someone at the Tor Project analyse these Blue Coat MiTM boxes and find a cross-signed intermediate signing certificate preloaded, with the option to load your own signing cert so one could MiTM with ease? This was more than a few years back...