Difference between revisions of "Security notes / Glossary"
m (→The bitter ex test) |
m (→Red Team) |
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Red Team is trying to imitate adversaries, blue team is defending. | Red Team is trying to imitate adversaries, blue team is defending. | ||
| − | |||
| + | They're originally military terms, for simulated conflicts, | ||
| + | basically adopted to test the robustness of strategies in the real world. | ||
| + | The idea was adopted by the security field. | ||
| − | |||
| − | |||
| − | + | "Red teaming" is usually meant as 'think as an attacker, not as a defender', | |
| + | so that we don't get stuck in strategies that we were taught, | ||
| + | but also test that they actually work. | ||
| − | |||
| + | ...sounds like a good idea, but what does it really mean? | ||
| + | How is it different? | ||
Isn't all security testing trying to get in? | Isn't all security testing trying to get in? | ||
: is it testing what wasn't considered in the design? | : is it testing what wasn't considered in the design? | ||
| − | :: no, you should be doing that anyway - you should check more what the designer thought of. That's why you were hired. | + | :: no, you should be doing that anyway - you should check ''more'' than what the designer thought of. That's why you were hired. |
: is it bringing in someone external? | : is it bringing in someone external? | ||
:: maybe, but isn't that called penetration testing? | :: maybe, but isn't that called penetration testing? | ||
| − | : is it finding new angles, rather than just running a few established | + | : is it finding new angles, rather than just running a few established tests? |
:: that can work well, but there's so many different established techniques that work and are important - that's ''why'' they are established | :: that can work well, but there's so many different established techniques that work and are important - that's ''why'' they are established | ||
| Line 303: | Line 306: | ||
::: It's also often practically infeasible to do exhaustively | ::: It's also often practically infeasible to do exhaustively | ||
| + | : if you inform the blue team, making them unusually vigilent, doesn't that ''exclude'' a lot of real tests? | ||
| − | : | + | : if the blue team is kept unaware, then is it really a blue team? |
:: In the exercise we're referring to, blue teams only exist when there are two teams doing an active exercise. | :: In the exercise we're referring to, blue teams only exist when there are two teams doing an active exercise. | ||
:: This ''may'' happen in network jobs, because there an IDS is part of the loop, and things may be set up as an exercise. | :: This ''may'' happen in network jobs, because there an IDS is part of the loop, and things may be set up as an exercise. | ||
Revision as of 14:26, 10 May 2022
| Security related stuff.
Practical
|
Attacks
Access control
Least privilege (principle)
The principle of least privilege means each actor in a system should be able to access no more than it needs.
For example, you can say
- your web server should be denied to real all of the filesystem, except its own documents
- your backup program should
- be able to read most everything, but...
- not be able to run anything (beyond its own components)
- not be able to write anything except to the backup disk and its own logs
This is part of why functional accounts are often created for each such part:
It's easier to handle this in broad terms even in simpler DAC setups, with just filesystem permissions.
When you want to crack down on this more thoroughly and more visibly, look at things like SELinux (because it adds MAC).
Note that the isolation in VMs and OS containers, are implicitly least-privilege as well: no connection to the outside unless permitted.
See also:
Discretionary Access Control (model)
Discretionary access control (DAC) means access to an object is at the discretion of the object's owner.
...more precisely, the identity of subjects.
Usually that's owner-based, though e.g. capability systems often allow transfer to other parts.
Mainly contrasted with MAC
Examples:
- permissions in most filesystems
Mandatory Access Control (model)
Mandatory access control (MAC) means that the system that decides to allow access between objects, instead of the object owners (though some systems apply MAC on top of DAC)
Often means labeling objects with particular categories, and having rules based on these categories.
Such (often-broad) labeling is often done for practical reasons: it often makes the rules simpler, which makes it more clear they express what you intended.
MAC usually means design up front,
and reconsidering that full design on each change.
This is also why it often assists DAC, because
- while MAC is good at partitioning off parts of a system in broad terms (e.g. web server may only read under /var/www regardless of permissions),
- MAC it is less flexible at anything you can't describe fully at the design stage (like people sharing specific files securely).
- while you can sort of implement DAC with MAC, this is often so messy
- to the point that it may be harder to verify as being correct
Role-Based Access Control
Role-based access control (RBAC) is focused on roles and role hierarchy, subjects and sessions.
It's a moderately detailed abstraction, considered a thing of its own, and a common reference for this sort of thing because these concepts cover a lot of typical needs of larger organisations
This makes it (possibly mainly the role part) a potential piece of of DAC, MAC and others.
https://en.wikipedia.org/wiki/Role-based_access_control
Attribute-based access control
Related notes
If you squint, there is sometimes very little difference between a category that a MAC system works on and a group that a DAC works on.
That is, very similar to users
The difference lies largely in who may change them - the admin, or the relevant user.
This is also roughly why there is value in mixing them. E.g. stricly separate web server, database, and other in terms of many resources. And have users as a third general pile, they can figure out among themselves and mostly just care about filesystem DAC anyway.
