prevention of an attack vector (e.g. XSS, HPP, CSRF)

learn more… | top users | synonyms

91
votes
2answers
32k views

What are rainbow tables and how are they used?

Where can I find one? Is there a pot of gold at the end? How do I protect against them? From the Area51 proposal This question was IT Security Question of the Week. Read the Sep 09, 2011 blog ...
60
votes
6answers
25k views

What techniques do advanced firewalls use to protect againt DoS/DDoS?

It is hard to protect a server against Denial of Service attacks, DoS/DDoS. The two simple ways I can think of is to use a server with much resources (e.g. CPU and memory), and to build the server ...
33
votes
7answers
3k views

Is there a difference between GET and POST for web application security?

I have 2 choices in sending data between 2 web applications. I encode the data in Base64 and append to the URL and retrieve these parameters at my destination application and decode the parameters. ...
20
votes
3answers
3k views

What steps should be taken to validate user uploaded images within an application?

Recently I have worked on a number of applications that need to process user uploaded images steps have been taken to validate the extension and the mime type. But what else can be done to ensure ...
31
votes
2answers
4k views

How can a Software application defend against DoS or DDoS?

Most of the solutions for DoS attacks are not at the application level. In case I am using a proxy server, what are the possible countermeasures for DoS at the application level?
23
votes
7answers
1k views

How can I protect a WordPress installation?

How do you go about protecting a default WordPress installation? What checklist do you use, best practices, tips and tricks, etc? Any recommendations on plugins, third-party tools are welcome.
82
votes
12answers
27k views

Why do sites implement locking after three failed password attempts?

I know the reasoning behind not letting infinite password attempts - brute force attempts is not a meatspace weakness, but a problem with computer security - but where did they get the number three ...
18
votes
5answers
1k views

Can you secure a web app from FireSheep without using SSL?

Assume that you want to give some web users privileged access to your website, but that you are unable (or unwilling) to offer SSL to all of them - at least past the initial login page. In this ...
12
votes
3answers
4k views

How can I prevent someone from accessing a Windows XP system via boot disk?

Apparently a computer system protected by a a login password, e.g. Windows XP, can be easily hacked by someone with physical access to it using methods like this one: http://www.raymond.cc/blog/...
61
votes
8answers
15k views

Should I change the default SSH port on linux servers?

Is there any advantage in changing the SSH port, I've seen people do that, but I can't seem to find the reason why. If you have a strong password and/or a certificate, is it useful for anything? ...
21
votes
3answers
15k views

Is there a way to mitigate BEAST without disabling AES completely?

It seems that the easiest way to protect users against the BEAST attack on TLS <= 1.0 is to prefer RC4 or even disable all other (CBC) cipher suites altogether, e.g. by specifying something like ...
28
votes
5answers
23k views

What is the correct way to implement anti-CSRF form tokens?

I am fully aware of CSRF and have already implemented some safe forms, but I have never been happy with the results yet. I've created tokens as a md5 of username, form info and a salt and stored it ...
20
votes
8answers
12k views

Can malware be attached to an image?

I have a small number of employees who use a company computer but these people aren't very tech savvy. They use an email client and a messaging client. I'm pretty sure they wouldn't click on .exe or ....
31
votes
6answers
7k views

Can malware be dangerous even when quarantined?

I am reading a book on network security and when talking about user confusion it writes: "It is not uncommon for a user to be asked security questions such as Is it safe to quarantine this ...
22
votes
3answers
3k views

Does overlaying the mouse on a virtual numeric keyboard really protect against keyloggers?

I just saw for the first time a new way to enter a password, at the Banque Postale (French Bank). You are given a virtual numeric keyboard and to type you can just leave the mouse cursor over a number ...
17
votes
5answers
1k views

How to best defend against Targeted Attacks?

We have seen this attack method grow as part of Advanced Persistent Threats (operation Aurora against Google or the G20 French Finance ministry attacks come to mind) but I have no doubt that even ...
9
votes
3answers
2k views

What is sandboxing?

In security discussions, the topic of sandboxing often comes up. What is application sandboxing? How does it work, and what security vulnerabilities does it prevent?
4
votes
2answers
9k views

HTML encoding to protect against XSS

While going through some references about protection against XSS i found that it is a good practice to encode data (entered by users) before using it to generate a dynamic page. I was not able to find ...
6
votes
3answers
625 views

Appropriate defense for 404s in my logs - persistent web scans from one region

This seems to be a fairly easy question to figure out, but I wanted to make sure. I've got about a thousand entries on one of my web servers with phpmyadmin in the connection criterion, but as I don'...
12
votes
5answers
6k views

QR codes that can't be copied - possible?

I assume this is impossible, but I need to find a barcode (that can contain a url, i.e., a QR style one). It has to be photographed by our smartphone app, but the image will not be changed over a ...
157
votes
2answers
21k views

What is DROWN and how does it work?

There is a new recent attack "on TLS" named "DROWN". I understand that it appears to use bad SSLv2 requests to recover static (certificate) keys. My question is: How? How can you recover static ...
15
votes
5answers
2k views

Securing a laptop against attacks (article)

I came across this article when looking for ways of hardening my laptop, and this guide seemed extremely thorough. It is perhaps overly paranoid, but it will be good to have a guide I can trust should ...
17
votes
7answers
8k views

Any comprehensive solutions for binary code protection and anti-reverse-engineering? [closed]

Does anyone know of good products with comprehensive binary hardening and anti-reverse-engineering features? Or better, has anyone seen an independent review comparing products that perform these ...
8
votes
5answers
8k views

What kind of attacks against home router's NAT do exist?

I always thought NAT was some kind of a security feature and I still think it is, because if it didn't existed the internet, respectively the clients behind NATs, would be even more insecure, since ...
18
votes
8answers
1k views

Ways to secure yourself from Firesheep kiddies and other sniffing

Just a few days ago I had my first encounter with Firesheep. Luckily I was the one using it. Well, it scared me into looking for ways to secure myself. So I have two questions: In exactly what ...
12
votes
7answers
2k views

Whitelisting DOM elements to defeat XSS

As we know, developers are responsible for correctly escaping/validating data provided by the user before rendering or storing them. However, we must agree that it's relatively easy to forget a single ...
8
votes
2answers
2k views

MIME sniffing protection

As it is known, older versions of MSIE (before 8) have a nasty habit of treating images as HTML if they "look like" HTML, which can lead to nasty vulnerabilities for sites that allow people to upload ...
11
votes
5answers
11k views

Can I block based on Mac Address?

Incase of dynamic IP's the hacker can work around by taking a new IP or use a Proxy, is it possible to make a ban based on Mac Address ? I want to block at the Webserver level so that unwanted users ...
5
votes
3answers
10k views

Resolving an IP address of a Remote machine to its MAC address

I wanted to know whether its possible to get the MAC address of remote node (computer/Access Point) if I know its IP address. I have heard that if someone sends you an email (even through gmail), you ...
5
votes
3answers
994 views

is it safe to allow external images to be attached to Blog or any Web content?

I am filtering all images that attached to any content of my blog: Check for file extension. Check content type using $finfo = finfo_open(FILEINFO_MIME_TYPE); I also save the image temporary on my ...
107
votes
4answers
11k views

How does ransomware get on people's computers?

I've noticed increased frequency of ransomware questions around Stack Exchange. Some of the people I remotely know had their devices recently infected as well. I'm starting to be concerned. When ...
12
votes
1answer
3k views

Preventing man in the middle attack

I recently did a man in the middle attack on my college LAN (for purely educational purposes:)). I simply wrote a raw socket application that pumped ARP reply packets advertising my MAC address with ...
10
votes
4answers
5k views

How effective are reverse proxies as a web application security measure?

How effective are reverse proxies as a web application security device? Which types of threats do they mitigate against and which don't they? For example are they more effective in preventing ...
20
votes
5answers
3k views

Designing in zero day attack mitigations

What are best practices / recommendations / strategies for mitigating zero day threats/attacks from a software development perspective?
8
votes
3answers
13k views

How to protect myself against paid DDoS services?

I am domestic user and I am getting attacked regularly by a guy that hates me. Here is the background story: that guy uses Skype resolvers (tools offered by paid DDoS services) to find out my IP ...
9
votes
3answers
638 views

Does Gmail 2-factor auth increase security on smartphones?

So I have enabled 2-factor authentication on Gmail, which means that if I log in on a new machine, it sends a token to my phone. Now, if I access Gmail from my phone, it seems like I have only one ...
1
vote
1answer
495 views

Have I done enough not be compromised through image uploading

I know that you can never be sure that you have done enough to be secure, and I also know that file uploading is hard to make correct. Before asking this question I read some of the related posts here ...
12
votes
2answers
1k views

Interpolique: transparently preventing SQL Injection and XSS with base64 encoding, what happened?

For the keynote at The Next HOPE a couple of years ago, Dan Kaminsky unveiled Interpolique (the talk is really fun btw). The problem he raised was how to defend against injection attacks, including ...
31
votes
10answers
13k views

Is it bad to have cameras using a static IP address?

I am about to move in a new house, and I would like to install some security cameras. The contractor told me that in order for me to check the videos recorded by the cameras in real time when I am ...
18
votes
3answers
8k views

DNS Amplification DDOS attack

During the weekend I made some tests to simulate an DNS Amplification DDOS attack. sending about 90Mb/s traffic I was able to generate about x.x Gb/s amplified traffic which sent our datacenter ...
14
votes
2answers
623 views

Detecting attempts to attack a website?

I am currently trying to implement some recommendations from OWASP AppSensor Project and I'd like to respond to the attacker when he tries to break into my website. Is there any resource covering/...
25
votes
6answers
2k views

User input data, is filtering enough or should it be parsed?

In a web application there could be two approaches to mitigate XSS attacks: all the input data could be filtered (removing all 'bad' data), or the input could be parsed, tokenized and output with ...
10
votes
2answers
414 views

How do you compare risks from your websites, physical perimeter, staff etc

In assigning budget rationally - ie proportionally to the risk in a particular area, how can you calculate the relative risks? I can think of examples where clients of mine have secured their ...
8
votes
1answer
1k views

Is it possible to recognise and prevent MitM attacks on devices which use self-signed SSL certs?

I use both Linux and Windows at work on a large enterprise LAN. The majority of the network configuration is out of my reach. Certain SaaS applications that are hosted locally on the enterprise LAN, ...
6
votes
2answers
1k views

Escaping rich text editor output

When having a rich text editor on a web application, what is the best way to escape HTML entities and prevent XSS attacks but keep the formatting (<b>, <i>, <u>, ...etc.) ?
13
votes
4answers
3k views

Possible to prevent Juice Jacking by only connecting USB pins 1 & 4?

According to this accepted answer, there is no phone on the market today that is immune from "Juice Jacking"*. I think an easy way to mitigate this threat is to have a filter that blocks USB pins 2 &...
9
votes
4answers
4k views

How can I detect and block bots?

For example, if I am on stackoverflow and I refresh my page several times in a row, it starts to think I am a bot and blocks me. How can I build something like this into my own site?
6
votes
3answers
585 views

Virtualization as a layer of security for desktop computers?

Given the amount of 3rd party plugins required to browse the web, I've been compelled to virtualize my online habits to gain an additional layer of security. There is of course some obvious drawbacks:...
6
votes
7answers
2k views

Should I prevent sending of GET requests for urls that are normally operated with POST request?

There is an url that is normally operated using POST requests (i.e. POST request is sent when user submits form). But attacker can form GET request with parameters that are sent in POST request. This ...
5
votes
2answers
359 views

FrameBusting script

It is commonly known that loading your site inside a frame on another site, can potentially expose your site to all kinds of ills, and in general is not a good idea if you have any sensitive data to ...