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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 ...
Monica Apologists Get Out's user avatar
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 ...
Trey Blalock's user avatar
  • 14.2k
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 ...
Conor Mancone's user avatar
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 ...
allo's user avatar
  • 3,451
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 ...
gowenfawr's user avatar
  • 73k
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 >> /...
vidarlo's user avatar
  • 16.6k
54 votes

Is it a bad idea to bypass login wall for a specified IP address?

You don't have to worry about spoofing the IP from a different connection, because returned TCP packets would not make it to the attacker in that scenario. So all you have to worry about is how easy ...
700 Software's user avatar
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,...
schroeder's user avatar
  • 131k
43 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 ...
ThoriumBR's user avatar
  • 54.6k
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 ...
Squeamish Ossifrage's user avatar
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 ...
André Borie's user avatar
  • 12.8k
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 ...
Steffen Ullrich's user avatar
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 ...
Daniel's user avatar
  • 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 ...
Anders's user avatar
  • 65.7k
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, ...
Steffen Ullrich's user avatar
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, ...
Kevin's user avatar
  • 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 ...
Arminius's user avatar
  • 44.9k
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 ...
VL-80's user avatar
  • 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 ...
Mario Trucco's user avatar
  • 1,569
19 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 ...
Josef's user avatar
  • 5,993
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....
mentallurg's user avatar
  • 12.5k
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 ...
Klamann's user avatar
  • 513
17 votes

Is it a bad idea to bypass login wall for a specified IP address?

As others pointed out, IP spoofing alone is not a problem here since the threeway handshake for TCP will not complete. BGP hijacking combined with IP spoofing could result into a somewhat theoretical ...
Teun Vink's user avatar
  • 6,938
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 ...
Ben's user avatar
  • 2,064
16 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 ...
schroeder's user avatar
  • 131k
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 ...
calloc_org's user avatar
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" ......
WaltZie's user avatar
  • 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 ...
Schwern's user avatar
  • 1,588
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 ...
Jacco's user avatar
  • 7,712

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