147
votes
Why avoid shared user accounts?
Alice and Eve work for Bob. Alice is a very good worker who does exactly what Bob asks her to do. Eve is a criminal mastermind hell-bent on destroying Bob's company.
Alice and Eve both share the same ...
91
votes
Why is it bad to connect internal systems to the Internet?
First, it might be best to fully understand the client (your boss's) needs. It's possible he or she only needs access to one small subset of the data on this server from anywhere and not necessarily ...
- 14.3k
78
votes
Accepted
Global variables and information security
Boycott Globals!
I'm stealing from Steffen Ullrich's comment, but the main issue with global variables is that they make it difficult to keep code well organized and maintainable. His link is a fine ...
- 31.7k
76
votes
Accepted
Can an identity provider impersonate me? (Can Facebook post Stack Overflow questions under my name?)
Yes, they can.
Simple answer: You authenticate in some way to your identity provider, usually via username and password. The bad admin can store the transmitted credentials and just re-use them. This ...
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76
votes
Accepted
Why is email often used as the ultimate verification?
This seems like a very wrong medium to send such information via.
Email is used for the same reasons Social Security Numbers get re-used as account identifiers in the US: Ubiquity.
Not everyone has a ...
- 73.3k
60
votes
Accepted
How can I prevent a user from copying files to another hard drive?
You can disable USB storage on Linux by blacklisting the module.
modprobe -r usb-storage
echo blacklist usb-storage >> /etc/modprobe.d/10-usbstorage-blacklist.conf
echo blacklist uas >> /...
- 17.5k
44
votes
How to prevent admins to access logs from their own activity?
The accepted solution to this is to not store the logs locally, but on a log server. Once the logs are there, you can restrict or limit access as you see fit.
In some log server/aggregator solutions,...
- 132k
44
votes
Accepted
Authentication versus Authorisation
once A gets falsely authenticated as B...
On any minimally secure system, this isn't how it happens. From the system's point of view, User B is authenticating himself, not User A. It was not falsely ...
- 55.5k
40
votes
If password expiration is applied, should door-lock expiration be applied too?
You asked, ‘if passwords should expire periodically, then should door locks expire periodically?’. Well, from a false premise you can derive any conclusion! The premise of periodic password ...
- 2,674
38
votes
Accepted
How can I publish data from a private network without adding a bidirectional link to another network
You can use a serial port. By default there are two data lines, one per each direction, plus a ground wire (which is irrelevant here). By disconnecting the appropriate line you can prevent ...
- 12.9k
37
votes
If password expiration is applied, should door-lock expiration be applied too?
Password rotation policies are in place to reduce specific risks which allow an attacker to get (and use) the user’s password. These risks are password reuse, credential phishing or other forms of ...
- 208k
30
votes
Why avoid shared user accounts?
Real story, happened at a friends workplace (jurisdiction: Germany):
A coworker of his rudely insulted clients via her company e-mail. She was fired for this. She did go to court. There, her lawyer ...
- 401
27
votes
Accepted
Accessing document using a 6 letter token
Brute forcing
So you have an alphabet of size 36 and 6 characters. That gives you about two billion different tokens. Lets say you have a thousand different documents. That gives you a chanse of one ...
- 65.8k
27
votes
Why is email often used as the ultimate verification?
While you correctly identified problems with e-mail, a mail based verification is still considered sufficiently secure for many cases. While there are alternatives like SMS based verification, ...
- 208k
25
votes
The teacher logged me in as administrator for doing a short task, is the whole system now compromised?
The teacher logged me in as administrator for doing a short task, is the whole system now compromised?
No.
but I was able to reset the administrator password with lusrmgr.
Now it is, ...
- 367
24
votes
Why is it bad to connect internal systems to the Internet?
Are there some reasons that connecting internal systems directly to the internet is a bad thing?
You're unnecessarily increasing the attack surface.
Here are problems to consider:
An attacker who ...
- 45.1k
21
votes
How can I prevent a user from copying files to another hard drive?
Client-server architecture
This is another approach that could make copying files much harder, but it requires investing more effort from your side.
Access to the information could be setup on a ...
- 1,254
20
votes
Can an identity provider impersonate me? (Can Facebook post Stack Overflow questions under my name?)
TL;DR:
A bad Facebook admin who can spoof your Facebook login can post bad stuff under your name on Facebook, and that is usually considered worse than posting a question on Stack Exchange.
My more ...
- 1,569
20
votes
How to handle refresh tokens
The point of having access tokens is that they can be used without checking for invalidation. You can have 10000 frontend servers users can access with the token without the need to ever ask some ...
- 6,011
19
votes
How can I prevent a user from copying files to another hard drive?
In addition to blocking USB (see other answers above):
Disable networking, because...
... otherwise user will use remote access to your machine, e.g. via scp or ftp, and copy files from your machine....
- 12.6k
18
votes
How can I publish data from a private network without adding a bidirectional link to another network
I love how much my search performance increases as soon as I am done posting my question ;D
Wikipedia to the rescue:
"Sneakernet is an informal term describing the transfer of electronic information ...
- 513
17
votes
Accepted
What is the difference between API keys and API tokens usages?
API keys are public, by intent. They are an authorisation mechanism, not an authentication mechanism (this is mentioned in your links). It does not matter how they are generated but it matters how ...
- 132k
16
votes
What are the security risk of enabling cors on localhost?
The answer really depends on what API you created and how it works.
This site gives a very good explanation on the goods and bads of CORS. In short, the author creates a fictional API that is used to ...
- 2,084
15
votes
Accepted
Does insert only db access offer any additional security
The short answer is "Yes", it does offer some additional security as you make it more difficult for an attacker to gain the information these outside users are entering.
The long answer is that a ...
- 266
15
votes
Why avoid shared user accounts?
You should use separated account in all contexts (security on the top).
Adonalsium example show you because it's required.
There are some rare situations where it is "not possible" or "not usefull" ......
- 339
14
votes
Why is email often used as the ultimate verification?
Email is the least worst option.
It's not just the ubiquity of email. Email is federated, standard protocol. No one entity controls email. Email is a marketplace. You choose your email provider. Don't ...
- 1,589
13
votes
RBAC0 RBAC1 RBAC2 RBAC3 -- What do they mean?
These are 'levels' for the NIST RBAC Model, as described in: The NIST Model for Role-Based Access Control: Towards a Unified Standard.(pdf)
They respectively refer to:
Flat RBAC
Hierarchical RBAC
...
- 7,752
13
votes
How can I prevent a user from copying files to another hard drive?
OK, I'm totally not a security expert and maybe this is completely off the mark (let me know in the comments!), but...
If you can secure the box physically (otherwise all bets are off), then maybe ...
- 1,050
13
votes
Accepted
How is MAC useful?
And with this, the permissions of something is mandatory, and are enforced so that even the owner cannot change them.
Imagine mysql running as a certain user. It has to read and write the database, ...
- 17.5k
Only top scored, non community-wiki answers of a minimum length are eligible