The first very likely scenario is given business logic says a web server application needs certain data, where "certain" is "pretty much all of it". So your application server in that DMZ has a database credential it needfully holds.
Which in turn is a credential an attacker can use to access "pretty much everything".
single person at a time
The majority of modern web applications will open a series of database connections. One application server limited to one DB connection for a public application is probably going to break the app.Overall, security people don't get the choice about "bowing" to business people in most of my experiences. I'm not saying scape goating never happens, but this
then just be clear that you are getting fired when the shit hits the fan.
What do you think the alternative is? Tell them you're quitting early on because they won't do what you say?I can present risks, and offer mitigations. More often than not, some get through easily, some never will, and it's those on the fence you work on constantly improving.
Now, sure, if the front ends query 10% of all records every day, then yeah, it only takes 10 days to get all the data, one query at a time, without triggering any alarms. They had 75 days. I don't know though, on any given day, what percentage of the population are getting credit checked? And did they have any alarms?
SELECT * FROM users WHERE ID = 10
Why not SELECT * FROM users where ID > 0
Honestly this is something I'd like to be able to put in place in certain areas, but I'm not aware of a sane strategy to do so existing.App server has no database access. No DB credentials, and no network access to the DB. It does, however, have access to a service that sits in front of the DB. It can ask the service:
GET /users/10
... and that's it. It gets one record. The service fronting the DB has a single query it can execute: SELECT * FROM users WHERE ID = ?
Sure, if someone can compromise the user-data service, then they have more access. But that's what defense-in-depth is: if an attacker compromises one system of yours, they don't get the crown jewels: they need to keep going, and each new attack they need to mount costs them more, and sometimes even makes them fail.But the development world has been turning on stored procedures for a while. You've got popular frameworks actively shunning the concept[0].
I've seen the topic on HN before and it's generally been the view that there is rarely a use case in modern times. We can't suddenly say everyone is expected to have everything in a stored procedure now that it's convenient.
[0] http://web.archive.org/web/20060418215514/http://www.loudthi...
The more modern equivalent, is to just have an "app server" that sits in between the web (DMZ) and db tiers. The app server can basically be just another web server that provides an API for the actual web server to use. So from the web server's point of view, it still has restricted access, but you get to write all the rules in your normal backend architecture/language rather than building them with stored procedures and triggers and all that.
Besides, the "rarely a use case" isn't the same as "never", and if you can envision any scenario where it would be worthwhile to go to extraordinary means to ensure security, I think "we have all the data needed to commit identity theft on half of all Americans" counts. If stored procedures is a convenient way for you to limit the impact of a breach from your web server/DMZ, then do it if you have data that important. Do 20 other things that are inconvenient too if it gives you defense in depth.
It also means that we can use access controls on the API (the stored procedures).
In my experience, allowing anyone to hit a database with SQL leads to poor code quality, bugs and performance problems. And security issues.
And this is exactly where the problem comes from. A web application should never be allowed to talk directly to the database.
You can argue that Target is not in the "we need to secure this treasure trove of data" business and so them leaking 40 million credit cards is just an unfortunate accident.
But when you sit on the PII of 150 million people then you need to be top notch security wise. I am sure the eventually inevitable courts will appreciate a company culture where admin/admin is acceptable.
How many jobs are out there for people who tell the "business" people what they want to hear, versus people who tell them hard truths about security? How many businesses succeed despite lax security -- gambling irresponsibly, yet winning?
It's much better, certainly. Companies should do that. But it's not obviously a panacea.
What I want to say is, it wouldn't surprise me to hear that the three main bureaus process millions of requests per day.
Oh, and also - all bureaus were replying to a request in less than a second. Quite impressive.
This underscores the importance of figuring out a better architecture. And not just for credit bureaus.
It is remarkable how resistant people are to the idea that you need to be patient while the world changes. Everyone is out for blood and gives not a fleeting thought about what would come after such a purge.
How do you read linux firewall documentation with the first example being old school public->DMZ->private? So your web server got hacked? That means what? Your database is across a single port through the firewall, and ACLs mean that any traffic arriving at the part from the DMZ CIDR can only do the limited set of queries that provide single-person-at-time. SSH from hacked box to database? Got a zero-day for the firewall (because 22 isn't open from there), and a zero-day for sshd (because its keys only). I know this and I'm not one of our hundreds of security people. (And as I'm not the security guy, if any actual security guys want to school me here, please do so!)
Sure, I agree that business peeps will say "Oh that's too expensive I don't care", but lets not pretend that we don't know how to do this.
Be clear, if you are the IT security guy, and you agree to bow down to "business" people (you're a business person) who tell you "No, that's too complicated", then just be clear that you are getting fired when the shit hits the fan.