But sometimes it is useful: after HeartBleed I wrote a TLS inspecting firewall that blocks heartbeat records and I know it really helped get some customers out of a deep hole (they were unable to upgrade the impacted software itself).
Often it is something in the middle; like firewalls that look at SNI and X509 certificates to block "bad" domains associated with phishing and other abuse.
I'll give the same spiel I give every time proxies come up: I am a donor to EFF, friend of privacy and the 4th amendment and I love the ACLU. I also recognize the legitimacy and importance of MITM proxies that inspect the content of SSL on a corporate network. It's not despotic to deploy company assets with company root CA certs that proxy TLS traffic to make sure a random employee isn't uploading credit card data to Box.
Except you aren't making sure, and there are many ways sensitive data can be exported. Let's be honest with ourselves here, these measures are often implemented under the guise of security but really are just liability and risk reduction approaches. The practical security benefit is very low IME, especially considering the burdens these measures put on employees' ability to work their best (and, as this article points out, burdens on others as well).
1) Upload a file via GDrive or Box 2) base64 encode the data andsend it to a remote DNS server over the course of several days via TXT record requests
As another poster says, it's all about reduction of risk. It's about balance. And on a corporate network that owns the workstation and server configuration, running a root CA cert and installing it in a gold load is pretty easy for the level of inspection and prevention it provides.
This is not the end all of security, either. It's one of many steps.
Exactly. It's a company resource. Most people seem to have / can afford a mobile device with cel/Wifi connectivity. Why should you feel so privileged to go to reddit, Gmail, Box, etc. on a bank network?
>Let's be honest with ourselves here, these measures are often implemented under the guise of security but really are just liability and risk reduction approaches
This is a fundamental misunderstanding of security. It is ALWAYS about risk and liability reduction.
As long as the inspection was transparent (which it was until the TLS 1.3 discussion started), employees mostly didn't know they were being monitored, and they didn't care even when they learned they were. Folks who got caught downloading porn or running their side-business over the work network were surprised that we were looking for that stuff, but no one felt like their privacy had been violated.
If you are going to spy on me, please disclose when and where. AFAIK w/HSTS sites they generally don't interdict the traffic (not because they don't want to but probably because they can't).
All the time spent implementing those "solutions" would be better spent deploying proper access control, so that retards that may inadvertently upload confidential data to box don't have access to the information in the first place. As a bonus, it also protects you better from malice and not only stupidity.
or the PDF they clicked on
These middleboxes are a way to spy on HTTPS connections between browsers and servers (where server can mean the load balancer at the edge of your server cluster), without having to ensure every device on the local network has a set of spyware installed on it.