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

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16
votes
2answers
24k 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? ...
16
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 ...
16
votes
5answers
25k 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 ...
16
votes
3answers
833 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
5k 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
357 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
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
641 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
13k 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
620 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
3answers
636 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
788 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
1k 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
4answers
639 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
4answers
5k 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
12k 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, ...
14
votes
3answers
18k 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
712 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
7k 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
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
14
votes
2answers
943 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
612 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
4answers
741 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
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
6answers
4k 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 ...
13
votes
4answers
6k 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 ...
13
votes
3answers
377 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 ...
13
votes
1answer
5k views

enable browser caching with HTTPS

I understand that sensitive data should not be cached (ie, you dont want to cache an HTML file with all of your bank account details in it), but there are some things that HTTPS protected sites should ...
13
votes
3answers
1k views

Elaborate websockets security

I'm interested in learning more about web sockets security. Read that web sockets were originally in Firefox, removed for security reasons and now added back in with the problem resolved: ...
13
votes
2answers
8k 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
2answers
214 views

Would suggesting a random passphrase during sign-up hurt overall security?

I've been looking for ways to improve security and security awareness for both internal and external clients and I happened upon the idea of generating a one-time, random "password suggestion" on the ...
13
votes
3answers
3k views

ASP.NET MVC security check list

I am planning to start a new web site on ASP.NET MVC 2 (3). Does anybody a full (if possible) check list of actions, approaches I should reach to avoid almost problems with security?
13
votes
3answers
1k views

What does a HTML filter need to do, to protect against SVG attacks?

I recently learned that SVG (Scalable Vector Graphics) images introduce a number of opportunities for subtle attacks on the web. (See paper below.) While SVG images may look like an image, the file ...
13
votes
2answers
7k views

CSRF protection and Single Page Apps

I am in the process of writing a thick client web app using Angular.js (single page app) and was wondering what are the best practices for securing the app using a CSRF token. Should I send a CSRF ...
13
votes
6answers
2k views

Securely building a local pentest lab in a VM

I'd like to set up OWASP WebGoat or a similar vulnerable web app in a VM (probably VirtualBox on Linux). For convenience's sake, I'd like to get it running on one of the primary machines I use (say, a ...
12
votes
3answers
3k views

Is it dangerous to show all the JavaScript functions in my web application? [duplicate]

Right now I'm developing a web application and it uses a lot of JavaScript functions so I'm putting all of them in different JS files to access from the HTML, but the functions are "easy readable" so ...
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 ...
12
votes
8answers
3k views

What chars should I not allow in passwords?

I am planning to develop a website that require that the users register a username and a password. When I let the user choose a password, what chars should I allow the users to have in the password? ...
12
votes
4answers
2k views

Preventing reverse-engineering of client application

I have a web service which is used by a Flash client. Both the service and the Flash client is produced by me (read: my company). The Flash client communicates with the server over HTTPS. One of the ...
12
votes
5answers
6k views

What is a DoS Attack and how does it differ from a DDoS attack?

Can some one explain to me the concept of Dos Attacks for web applications ? Also what is the distinction between Dos and Distributed Dos ( ie DDos) attacks ? Wikipedia says : In computing, a ...