All extensions disabled due to expiration of intermediate signing cert

I’ll still keep using Firefox since I recognize the importance of browser diversity and the hazards of a Chrome monoculture (that and vertical tabs), but, yikes.

Still, this type of oversight seems all too common even in large companies. I remember several cases from Fortune 500 companies in the past few years alone. What would be a good way to automate checking for them? Has anyone developed a tool designed specifically to avoid certificate expiry disasters?

You can find lots of programs like this one to monitor certs:

https://pypi.org/project/check-tls-certs/

I run one daily from cron and have it email me a report with the days to expiration for the certs I’m responsible for, even for certs that auto renew. I don’t filter the email. Daily is not too frequent for it to go to my inbox, but frequent enough that I’ll notice if it doesn’t mail me. YMMV.

Discovery of all the certs is what I think is the harder problem.

I agree. What can be done to prevent developers from adding a certificate dependency without monitoring during the move-fast-and-break-things days of early development, which then sits for X years as developers come and go, and nobody notices until it fails?