An application that is accessed over a network such as the Internet or an intranet using a browser.

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17
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2answers
26k views

Specific risks of embedding an HTTPS iframe in an HTTP page

I need help listing the specific risks of embedding an HTTPS iframe that enables credit card checkout inside of an HTTP page. Are there security issues with embedding an HTTPS iframe on an HTTP page? ...
17
votes
4answers
6k views

How to implement non-password authentication in a web site

In an answer to this question about pw reset, D.W. says: Lastly, consider non-password authentication. Passwords have many problems as an authentication mechanism, and you might consider other ...
17
votes
3answers
3k views

What is the point of the same-domain rule for xmlhttprequest when script tags/JSONP can cross domains?

I get that I don't want a page loaded from stackoverflow.com to be able to request gmail.com on my behalf and read my email--but this seems to be simply a cookie issue. Since JSONP bypasses ...
17
votes
1answer
3k views

What is a Web Application Firewall?

What is a Web Application Firewall (WAF) and what are some of the things to look for in an effective one? Why would you deploy a WAF instead of just an IPS?
17
votes
5answers
27k views

How can I find subdomains of a site?

One of the things I need to do from time to time is to find subdomains of a site for example. Starting with example.com sub1.example.com other.example.com another.example.com I'm ...
17
votes
1answer
3k views

Best way to secure javascript front end/REST back end architecture web site?

I would like to build the following project: public REST API back end which can be accessed by any authenticated client. front end with static files in HTML/CSS/Javascript with Backbone.js jQuery ...
16
votes
6answers
8k views

Is showing your IP address in the URL a bad practice?

Someone told me that showing your IP address in a URL (like hxxp://45.67.134.34/default.html) is easier to hack. Is that true? I could trace any domain name and get its IP number as well.
16
votes
5answers
3k views

Is it possible to inject values in a drop down list?

Say a ASP.NET page, or any html page for that matter, has a drop down list with a bunch of prices. On posting the page, the code looks at the selection of the drop down list for a computation. Is it ...
16
votes
6answers
5k views

Is XSS a server-side or client-side vulnerability?

My colleagues claim that XSS is a vulnerability on the server side. I always thought that this is a client side vulnerability. Which one of us is correct, and why?
16
votes
3answers
840 views

Getting a manual security code review done - What to watch out for?

We have a PHP application that we want to get code reviewed from an external security consultant, but I'm not clear on "how to" go about that process. We did specify what kind of tests he should be ...
15
votes
3answers
6k views

Cross Site Scripting without special chars

I'm testing a web application and I found a XSS vulnerability. I can break a tag and inject some code to the application but nothing potentialy dangerous for the client. The application has a filter ...
15
votes
7answers
367 views

Is a “security measure” that doesn't provide a security benefit actually harmful?

If a security measure is implemented that doesn't provide any additional security benefit, can it be considered harmful? As an example, consider a login page where the user is asked to enter their ...
15
votes
6answers
13k views

Why are iframes allowed at all in modern browsers?

I read a number of IT security blogs (though I'm no security expert), and it seems a significant percentage of exploits in the wild are delivered through adding malicious iframes to a hacked website, ...
15
votes
3answers
14k views

Does X-Content-Type-Options really prevent content sniffing attacks?

In Tangled Web Michal Zalewski says: Refrain from using Content-Type: application/octet-stream and use application/binary instead, especially for unknown document types. Refrain from returning ...
15
votes
4answers
2k views

Web Security Cheatsheet / ToDo list

Can anyone suggest a cheatsheet or ToDo list of web site and application security? A local small business owner prompted a question about web security, basically her company website just got XSS ...
15
votes
5answers
656 views

What are the most important security checks for new web applications?

I'm wondering what are the top priority security checks you should make befor launching a new webapp? I'm guessing brute force vulnerabilities and cross-site scripting. What are the other things you ...
15
votes
4answers
14k views

Ensure web service only accessed by authorized applications

Preface My mobile app allows users to create accounts on my service. In addition to being able to log in with external authentication providers, like Facebook, I want to give the user the option to ...
15
votes
3answers
629 views

Does signing out of a website ensure no-one can cookie hack?

If I click the signout link of a website, does this mean it is not possible for someone to hijack my cookie and sign in with it? While I'm logged in, is it possible for someone who has access to my ...
15
votes
4answers
1k views

Is it safe to store and replay user-provided mime types?

If a user uploads a file but modifies the request by setting the mime-type to something arbitrary, like "superdangerous/blackhatstuff", is it safe for me to send the same mime type back to a different ...
15
votes
2answers
1k views

How can I test my web application for timing attacks?

race conditions, etc. Are there automatic tools for this? What manual techniques should I use? From the Area51 proposal
15
votes
3answers
657 views

Are there any decent web app security scanners that can integrate with a build server?

I've spent a lot of time in TeamCity recently and the nightly code quality metrics coming from the dupe finder, FxCop and NDepend have been great. What I'd really like to do is find a decent web app ...
14
votes
5answers
799 views

What is better, an established framework or a homebrew solution?

Recently, a website related to our university was hacked along with many others. This led to a general discussion1 on how to secure the website in the future. Anyway, there is one point that was ...
14
votes
6answers
2k views

Is this login security enough?

I'm coming up with my next login system for admins of an e-commerce website, which will have this: login form is SSL secured password is converted to SHA-256 before being transmitted (bcrypt is too ...
14
votes
3answers
7k views

Is the Facebook login form using SSL without https in the URL?

If I go to http://facebook.com, I am not redirected to https://www.facebook.com. If it doesn't have https in the URL, can the login be secure? Usually I am redirected to an https page on other sites? ...
14
votes
3answers
2k views

Are combined sign in / up pages dangerous, and how to improve them?

I'd like to code a combined sign in/up page like the one in the picture below. My colleague said this will allow spammers/hackers to see what email addresses are registered with our system and ...
14
votes
4answers
685 views

How to protect off-the-shelf web applications?

As an exercise, please consider the following: If you are faced with having to deploy off-the-shelf web applications that you are unsure about the vendors security coding practices, which techniques ...
14
votes
1answer
9k views

Why use an authentication token instead of the username/password per request?

The author of http://stackoverflow.com/a/477578/14731 recommends: DO NOT STORE THE PERSISTENT LOGIN COOKIE (TOKEN) IN YOUR DATABASE, ONLY A HASH OF IT! [...] use strong salted hashing (bcrypt / ...
14
votes
4answers
6k views

Is AJAX fundamentally insecure?

Possible Duplicate: How to do Ajax securely? At my workplace many people believe that AJAX is fundamentally insecure. I am under the impression that AJAX is exactly as secure as any other ...
14
votes
2answers
2k views

How to not reveal that you are using PHP?

I'm bulding a website but some webtools and browser plugins allows anyone to get information on which technologies the website has been built. Is there any Alternative to not reveal that we are ...
14
votes
6answers
5k views

How do I get started with security? (beginner) [closed]

I have been working in web development for a fair amount of time. I am looking at developing in either Python (Django etc.) or PHP. I am new to security. Where do I begin looking? What are basic ...
14
votes
3answers
20k views

Why does Hydra return 16 valid passwords when none are valid?

I've been playing around with Hydra and DVWA and I've hit a bit of a snag - Hydra responds letting me know that the first 16 passwords in my password list are correct when none of them are. I assume ...
14
votes
3answers
3k views

Best practice in web application security authentication to avoid bruteforce attack

I want to cover the possible cases of attacking. My application already has captcha and two-factor authentication, but how can I avoid a tiny attack without annoying my users? The possible cases that ...
14
votes
4answers
7k views

How to protect against login CSRF?

http://seclab.stanford.edu/websec/csrf/csrf.pdf points out that most CSRF protection mechanisms fail to protect login forms. As http://stackoverflow.com/a/15350123/14731 explains: The ...
14
votes
4answers
734 views

Database Encryption Security

I am encrypting and decrypting my database data from my web applications API. If my web server is compromised, what is to keep someone from using that same method to retrieve the data? For example, ...
14
votes
3answers
4k views

Should security question answers be case-sensitive?

Question In the case of security questions being used to reset an account password, what is considered best practice for handling case-sensitivity on the security question answers? Scenario An ...
14
votes
4answers
8k views

Session Hijacking - regenerate session ID

Does regenerating the session ID on each request mitigate the probability of a session hijack enough to be worth implementing? I would imagine combining a check for REMOTE_ADDR vs the REMOTE_ADDR ...
14
votes
3answers
5k views

Is it possible to use a GPG or SSH key for web based authentication in a secure fashion?

Let's say hypothetically I am writing a web application targeting technically inclined, security-conscious users who have no problems generating and using GPG or SSH keys. Is it possible to use said ...
14
votes
2answers
1k views

Does it make sense to hash a session id before passing it to an advertisement partner?

My company runs a webshop. We work with a partner that gives discount vouchers to our customers after they buy (the vouchers can be used in other online shops) and also gives vouchers for our shop to ...
14
votes
2answers
621 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 ...
13
votes
6answers
3k views

Is it a security issue to allow nearly identical email addresses when registering?

Say you have a website where it is possible to create accounts for all of the following email addresses: 'test@test.com' 'test@test.com ' 'test@test.com;' 'test@test.com;test2@test.com' Should this ...
13
votes
6answers
3k views

How secure is redirecting user from http://normal.bank.com to https://secure.bank.com?

I have an application. Which works on http, http://normal.bank.com. But for log-in, performing any action, etc. I am rediecting user to https://secure.bank.com, where user can login and perform ...
13
votes
5answers
3k views

Solution to allow JavaScript input but prevent XSS

We have a simple Blog system that allows users to input html and JavaScript to build a blog page. I'm aware that allowing javascript open up the door to xss attacks. We do however need to allow users ...
13
votes
6answers
3k views

Filter user input before the database or upon display?

Given a web application where user data must be properly escaped to avoid XSS, is it better to try to remove the "bad stuff" before it enters the database, or is it best to allow it in the database ...
13
votes
4answers
747 views

Custom socket server on the internet running as root

We are writing a custom socket server which runs on a high port. Until recently, it has been running behind a corporate firewall. Now, it has been decided that the server should be taken outside the ...
13
votes
7answers
4k views

Should we force user to HTTPS on website?

Should we force website from HTTP to HTTPS , one of the method is using .htaccess: RewriteCond %{SERVER_PORT} 80 RewriteRule ^(.*)$ https://www.example.com/$1 [R,L] But what I notice is that some ...
13
votes
3answers
30k views

How can I use this path bypass/exploit Local File Inclusion?

I have tried to run a vulnerability scanning script (Uniscan 6.0) on some websites and then I found a site which is exploitable with this following path. (included a word "invalid" , params/website ...
13
votes
2answers
9k views

What is the benefit of the scope in OAuth2?

In the question, substitute scope with state. Since there is an answer based on the wrong question, I'll let everything below as is. The answer is useful nonetheless. This question refers to ...
13
votes
4answers
12k views

What SSL key should I make for IIS: RSA or DH? What bit length is appropriate?

I'm creating an SSL cert for my IIS server and need to know when I should choose the Microsoft RSA SChannel Cryptographic Provider or the Microsoft DH SChannel Cryptographic Provider. Question 1 Why ...
13
votes
3answers
387 views

Malicious QR Code and Mitigation

I just started reading a little on QR code, so I'm not entirely familiar with QR Code capabilities, but a thought crossed my mind today. I scanned a QR Code on a postcard I received, and it ...
13
votes
6answers
10k views

Disable insecure/dangerous PHP functions

Typically my job description limits me to code-review of web applications. More recently I've been asked to assist with some server-side PHP optimization where, although I am familiar with it, I lack ...