239
votes
Accepted
What is DROWN and how does it work?
To understand the attack, one must recall Bleichenbacher's attack from the late 20th century. In that attack, the attacker uses the target server as an oracle. When using RSA-based key exchange, the ...
- 323k
239
votes
Accepted
Why is the OS obfuscation defense against "It's a Unix system!" not widely implemented?
Before I tear your idea apart, let me say that it's a really interesting idea and it was super fun to think about.
Please continue to think outside the box and ask interesting questions!
Alright, let'...
- 58.2k
91
votes
Why is the OS obfuscation defense against "It's a Unix system!" not widely implemented?
Mike's answer says basically everything I have to offer about why this is a bad idea from a development perspective (and, as Ghedipunk's comment says, an unusable security feature provides no security)...
- 43k
83
votes
Accepted
Someone knows my IP and is threatening to DDoS me
ISP's have ways of dealing with DDoS attacks targeting one or more IP addresses on their network. See How can ISPs handle DDoS attacks? for some interesting reading on this subject.
What you are ...
- 21.2k
79
votes
Accepted
Security implication of telling the user they can't login because of too many attempts from IP
Absolutely do not message end user telling them why login failed. You are giving a potential attacker critical information to aid them in attacking you application.
On the other hand, not telling a ...
- 44.3k
74
votes
Accepted
How does ransomware get on people's computers?
According to the IBM X-Force Threat Intelligence Quarterly Report, fourth quarter 2015, the primary sources of ransomware attack are unpatched vulnerabilities, drive-by infections, and spear-phishing ...
- 818
66
votes
I detected someone probing my site for weaknesses, what can I do about it?
Welcome to the internet! This is the normal situation, business as usual.
You don't have to do anything, but to harden your website. Probes like that occurs all the time, on every site, day and night....
- 52.1k
54
votes
Accepted
Why do hackers scan for open ports?
To run an exploit, an attacker needs a vulnerability.
To find a vulnerability, the attacker needs to fingerprint all services which run on the machine (find out which protocol they use, which programs ...
- 49k
53
votes
Is it bad to have cameras using a static IP address?
Static or dynamic IP is a non-issue.
But since you brought up cameras, you should know that many IP cameras have VERY poor security. Many of these cameras have a known bad firmware in them that ...
- 21.6k
47
votes
Someone knows my IP and is threatening to DDoS me
Contact your ISP’s security team and explain your situation. They should be able to help you change your IP to a new address.
- 33.9k
45
votes
How does ransomware get on people's computers?
While the measures you describe in your question are not wrong, they are not correct either:
Documents are not safe to open either.
Often times, exploits come in the form of interestingFile.txt.exe.
...
- 14.4k
44
votes
Accepted
Barcodes as an attack vector?
Yes, barcode scanners present a potential vulnerability. You need to prevent attacks from this vector in the same way you'd prevent attacks from any input vector, such as a network connection or a ...
- 33.9k
43
votes
What is DROWN and how does it work?
The answer by Thomas is wonderful. There is just one thing that seems understated: e-mail servers are broken security-wise... by default and by design.
default: just look at the default postfix ...
- 664
42
votes
Accepted
Is it bad to have cameras using a static IP address?
I would consider another contractor, since that statement doesn't precisely increase my trust in his knowledge/skill.
The correct way of setting up a security camera system so you are able to check ...
- 5,211
41
votes
What can a company do against insiders going rogue and negatively affecting essential infrastructure?
What things can be done to prevent sudden rogue insiders from
negatively impacting essential infrastructure using techniques they're
privileged to do?
In practice, very little. But to explain ...
- 72.4k
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 ...
- 12.7k
33
votes
Accepted
What can a company do against insiders going rogue and negatively affecting essential infrastructure?
Two-man rule - configure your systems so that all privileged access requires two people.
This could be a physical control - privileged access can only come from the NOC, and inside the NOC people ...
- 32.9k
32
votes
Accepted
What are the security issues with "eval()" in JavaScript?
eval() executes a string of characters as code. You use eval() precisely because the string contents are not known in advance, or even generated server-side; basically, you need eval() because the ...
- 323k
31
votes
Accepted
How to prevent "cost attacks" on AWS?
AWS allows you to set budgets, and alarms based on your current rate of spending. Those would be useful to control your spending. In theory, you could also set billing-based automation to start ...
- 3,998
30
votes
Why is the OS obfuscation defense against "It's a Unix system!" not widely implemented?
If your objective is to deprive an attacker of ls and cat, there's an even better alternative to obfuscation: just don't install those utilities.
While I wouldn't say this is a widely implement ...
- 725
28
votes
Accepted
Fake UserAgent visitor attack?
Every computer with a public IP gets this kind of attention permanently. There's nothing you can do to stop it (I once tried to complain to the provider owning the offender's IP, never got a reply and ...
- 10.1k
27
votes
What can a company do against insiders going rogue and negatively affecting essential infrastructure?
One approach is to accept that rogue actions cannot be prevented and focus on making sure the damage can be repaired. For example, make sure the routers have a separate control plane via which they ...
- 540
27
votes
Someone knows my IP and is threatening to DDoS me
Not enough information for a qualified answer. I will make some assumptions and spell them out. Basic assumption: You actually care about being DDoS'ed (you earn money doing live streams or something)....
- 10.2k
23
votes
Accepted
Are short usernames a security concern?
The username is not a secret; any determined attacker will be able to find out the names of users on your system.
What does improve your security, is if there is no remote access for "root", "guest", ...
- 5,504
21
votes
Is it bad to have cameras using a static IP address?
The only difference between the static IP address your technician is referring to and a dynamic, changing address in this situation is that one never changes, and the other does (how frequently ...
- 652
19
votes
Accepted
Why is the Wikileaks site still accessible? How come it hasn't been hacked?
Why haven't other foreign powers hacked or DDoS attacked it in the past when it posted information they didn't want public?
Attacking the Wikileaks website to withhold information is ineffective. The ...
- 44.3k
18
votes
Accepted
Vim Modeline Vulnerabilities
Although in theory modelines shouldn't allow you to do anything bad, sanitizing modeline functions input is hard. There have been several security issues in the past that allowed arbitrary command ...
- 465
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
The Perfect Mousetrap - Can a sandbox system be designed such that it's identical to an actual computer?
Yes, it can be done as (theoretically) every "computing device" is computationally equivalent to every other computing device. Look up the Church-Turing thesis if you are interested.
However your ...
- 1,911
Only top scored, non community-wiki answers of a minimum length are eligible