79 votes
Accepted

Is an up-to-date browser secure on an out-of-date OS?

Do not use an outdated OS, even with a modern browser. Assuming that after that day I still use an updated browser, is it true that I'm still safe? No, you cannot avoid browser-based security ...
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  • 63.8k
56 votes
Accepted

How does an attacker get access to hashed passwords?

There are any number of ways: SQL injection Leaked backups Disgruntled employees leaking them Any kind of breach of the server that allows code execution. As you can see there are many, many ways ...
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  • 64.2k
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 ...
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  • 48.8k
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 ...
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  • 33.6k
37 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 ...
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  • 12.7k
33 votes
Accepted

Is email from my WordPress site a hack or just a normal comment?

The "Code" is "patching" your WordPress installation (wp-comments-post.php) and sending some information to several servers (probably c&c). Also, it is removing itself from the database. In other ...
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  • 684
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 ...
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29 votes

How does an attacker get access to hashed passwords?

There are many methods. Here are some I can think of off the top of my head. Now I might be a little wrong with the syntax as I haven't bothered to test it out right now, but in general, these are ...
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  • 22.5k
28 votes

NTP DDoS Attack on Home Servers

As an immediate mitigation, shut down your NTP service until you can get it secured properly. Your computer's clock won't (or at least, shouldn't) drift too much in a day or two. You'll still be ...
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  • 34.4k
27 votes
Accepted

Attack vector, attack surface, vulnerability, exploit: Where is the difference?

All 4 terms are very different: Describes the Attack: Attack Vector: the 'route' by which an attack was carried out. SQLi is typically carried out using a browser client to the web application. The ...
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  • 123k
17 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 ...
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  • 493
16 votes

Is email from my WordPress site a hack or just a normal comment?

This is a hacking attempt that contains a special combination of characters that hides the malicious payload code using Base64 encoding. The hidden code relies on an older version of WordPress being ...
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16 votes

Barcodes as an attack vector?

Many barcode scanners are treated by the operating system as a type of keyboard. This gives them exactly the same attack surface as somebody typing in the barcode's information at the keyboard. As ...
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  • 34.4k
14 votes

Attack scenarios of the new Bash vulnerability

The easiest way to test a web server via HTTP request is to inject the bash command through the user agent. Example: $ wget -U '() { :;}; /bin/bash -c "echo vulnerable"' http://example.com/some-cgi-...
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14 votes

What are the security issues with "eval()" in JavaScript?

eval() is a possible vector for cross-site scripting. Under normal circumstances, an attacker attempting XSS might want to get script <script></script> tags past whatever encoding, filters ...
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  • 6,797
13 votes

Can the Windows Schannel vulnerability be exploited by visiting a website?

What is known about possible attack vectors for this exploit? Can it be exploited simply by visiting a website if you haven't applied the update? From [Dailydave] More info on SSLMAGEDON: Our friends ...
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  • 704
13 votes
Accepted

How can I find my home network's vulnerabilities when opening it for VPN connections

Well, open port does not necessary mean that anyone can enter. If you have an open port on a router/modem with nothing listening behind, then there is nothing to compromise. Of course, this won't ...
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  • 13k
13 votes

Is an up-to-date browser secure on an out-of-date OS?

One benefit of the newer operating systems, like Windows 10 over Windows 7, is that they have more advanced features built in to the operating system to protect against entire classes of ...
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  • 131
12 votes
Accepted

Are in-store computers a security risk?

This is a great question and one that these organizations have probably put varying amount of thought into. I can think of a few different scenarios regarding systems being out in the open like that. ...
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10 votes

NTP DDoS Attack on Home Servers

NTP has one of the highest request to response size ratio, is over UDP, and as such is highly preferred as a method for reflective DNS amplification attacks. Cloudfare was recently the target of the ...
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  • 1,387
10 votes
Accepted

What is the intended attack vector of this email?

Such question merely asks for opinions as only the sender really knows his own intent, other people can only guess. I suppose that in your question you kept the real email address: admin@...
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9 votes

Is this an attack and how can I fix it?

If you ever need to check a suspicious URL, you can use a service like urlquery to check if it has a malicious reputation, the HTTP transactions that take place, any java script that runs, etc etc. ...
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9 votes
Accepted

Is Maven a plausible vector of attack?

It certainly was in the past. See http://blog.ontoillogical.com/blog/2014/07/28/how-to-take-over-any-java-developer/ Maven Central supports HTTPS, as of July 2014. Maven Central requires PGP ...
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9 votes

How does an attacker get access to hashed passwords?

One addition to Mark Buffalo: 7. Man-in-the-Middle attack. Watching unencrypted traffic can often reveal a password hash. In a pass-the-hash scenario, systems will trust the hash and the password ...
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  • 1,141
8 votes

How to protect contact forms against being misused for mass-mailing?

You're right that allowing arbitrary, unauthenticated internet users to control both the content and the recipient of email messages sent by your web service (i.e. your website's "contact us" form) is ...
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7 votes

What are the most common infection vectors for personal computers?

I'm going to reproduce my answer to this question from my website, DecentSecurity.com You get tricked "But I'm too smart to get tricked." - You Being tricked isn't strictly related to ...
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7 votes
Accepted

Difference between local and physical attack vector in CVSS version 3?

An issue of "absence of logout button" is absolutely not a physical vector. Physical means you have direct physical access to the server, as in you're standing right in front of it. A more appropriate ...
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  • 132k
7 votes
Accepted

can a power bank be used to plant malware?

A pure power bank likely cannot - most of them have the data lines not connected to any chips, but rather to resistor networks. However, someone could easily make something that appears to be a power ...
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  • 6,281
6 votes
Accepted

Regular Expressions for common exploits

The best solution would be to implicitly deny, i.e. allow exactly the data you want, but no other. You could write regexps matching all input that's not according to your filter to find any odd ...
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6 votes
Accepted

Malicious *URLs*?

Actually this is very timely as there's a relatively new attack where the data passed in the URL is the attack vector. Reflected File Download abuses non-malicious servers by passing them malicious ...
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  • 60.7k

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