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

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AES using derived keys / IVs. Does it introduce a weakness?

I'm looking for an efficient way to encrypt multiple fields in a database with AES using a single global key, used throughout a large web application. Obviously in order to re-use this key, a unique ...
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3answers
1k views

localStorage for apps over https. What expectations are there?

I run an online gradebook. To keep student data private, I transfer all data over https. Now, I'd like to use localStorage to avoid redundant calculations and server requests. However, according to ...
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4answers
1k views

Is there a typical step-by-step A-Z process for testing a Web site for possible exploits?

I'm interested less in the tools of the trade (there are many questions here already about that), and I am interested more in the process by which you would go about using those tools. So for ...
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2answers
5k 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 ...
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2answers
642 views

User-specific Subdomains : JavaScript security

If I provide a public-facing website for users on my website at their own subdomain (e.g. bob.myapp.com) under their own control, can I allow them to execute arbitrary JavaScript without putting my ...
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1answer
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Strict Transport Security — max_age value

I've been wondering what max-age should the HTTP Strict Transport Security header have. Both paypal and lastpass sites leave it very low: 500 (seconds = bit over 8 minutes) market.android.com has it ...
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1answer
1k views

How to make SQL injection in PostgreSQL's tsquery?

I think there is SQL injection vulnerability in an application I'm testing. This is seen when I enter malformed parameters into a search form. All exceptions are shown in format: PHP raised unknown ...
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4answers
5k views

Is client side encryption really better than server side?

Web application may encrypt all user data at client side to convince users that it can't decrypt them. When user enters password, it's used to encrypt data in browser and then it's sent to server in ...
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2answers
4k views

Keeping user session alive - security considerations

We have recently developed some functionality for our web app to allow a user to remain logged in indefinitely, and are interested in knowing the security ramifications of doing so. The goal of this ...
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6answers
1k views

when is it safe to click through an SSL warning message?

How does a user know if it's safe to click through scary browser warnings about SSL certificates? Ideally, a user should never need to click through these warning messages, but sometimes honest ...
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7answers
345 views

Aren't permanantly logged in accounts inherently insecure?

The basic premise behind a "keep me logged in until I log out" feature is a cookie is stored with some identifier that is used to log the user in again when returning to the site. While these ...
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4answers
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Can anti-CSRF token prevent bruteforce attack?

I am not much experienced with brute force attacks but I was wondering Suppose, you have a website www.example.com and you want to do brute force attack on that login form but that login form is ...
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17k views

Is there any SQL injection for this PHP login example?

I want to write a login form, and I got one example from the web. I want to know, if there is any SQL injection for this code? If there is, what could the exploit's web form entry look like? This is ...
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3answers
635 views

How does an attacker approach a website?

What is a typical mindset and method of approach? What are they likely to try first? At what point does a novice give up versus an expert? How would an automated attack differ from a manual one?
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9answers
403 views

What is the proper way to view the sourcecode of a website?

I recently heard that Firefox makes a second HTTP request when the sourcecode is requested. Is this true? Does this mean the webserver may issue alternate source from the original? Lastly, is ...
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6answers
2k 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 ...
8
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4answers
2k views

Is using HMAC to transmit a password OK?

I'm writing a small webapp and I don't want to transmit login passwords as cleartext. As I don't have SSL available I've written a one-time challenge system which sends a random string with the login ...
8
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3answers
687 views

How are large tech sites such as LivingSocial, Zappos, LinkedIn and Evernote hacked?

How are large tech sites such as LivingSocial, Zappos, LinkedIn and Evernote hacked? (i.e. how is their entire dataset of users obtained?) LivingSocial - 50 Million Users Exposed Zappos - 24 Million ...
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3answers
323 views

Does concealing server software versions have a notable effect on security?

Web servers can add Server, X-Powered-By and similar headers into HTTP responses. Looks like the consensus is such headers should be removed so that automatic vulnerability scanners don't immediately ...
8
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2answers
320 views

What is secure enough for web applications?

we intend to build a network in a small health center with No Internet Access it is expected to have 30 terminal machines, all machines will use an electronic medical record web application we want ...
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3answers
8k 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 ...
8
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2answers
787 views

Should user be allowed to save password in browser?

The auditing company found a bug "The Auto-complete form attribute is set in password field". They suggested to disable autocomplete for this field to prevent disclosure of it "when working on shared ...
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3answers
2k views

How bad is a Self Contained XSS attack?

Some of you might be familiar with this attack called Self Contained XSS. I recently stumbled upon this article about it. So how bad this kind of attack can be, even though this doesn't have access to ...
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3answers
254 views

Securing an E-commerce site

I'm building a custom e-commerce site, and the user will input their credit card details on the site instead of being directed to the payment gateway's site. I'm confused as to what the critical ...
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4answers
4k views

Is it okay for API secret to be stored in plain text or decrypt-able?

Aren't API keys considered usernames and API secrets considered passwords? Why is it that API servers like Amazon Web Services allow you to view your API secret in plain text? It makes me think they ...
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6answers
2k views

Fortify360 - Sinks & Sources - Vulnerability count

In an application security environment, I use Fortify Software's Fortify360 on a daily basis. One of my biggest hurdles is explaining the numbers (sources vs sinks) Fortify flags each location in ...
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1answer
7k views

Why is it so hard to close onion domains (e.g. The Silkroad)?

A few months ago when I started to experiment with bitcoin I came across The Silkroad (only accessible via Tor) For those who do not know what Tor is and who do not want to waste their time ...
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2answers
616 views

Isolating Web application hosted on same web server

I am working on a scenario if we have two or more web application hosted on a same server. Let says Web application X is vulnerable so how can i be sure that it will not effect the other web ...
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2answers
264 views

Is there any risk related to allow user to give an URL as their image profile?

Building a website, I'd like to allow users to specify an url that point to an image that will be used as a profile picture (included in the HTML DOM as a ). But before doing anything stupid, I was ...
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2answers
4k 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 ...
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5answers
3k views

Does setting httponly prevent stealing a session using XSS?

If a session token is stored in a cookie that has httponly set, is there any way that a XSS vulnerability could allow a malicious user to steal a users session token?
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3answers
3k views

Should web sites disable form autocomplete on all forms?

I've noticed that some web-app security scanners flag the 'Autocomplete' feature of some websites (in the username/password fields) as a security risk and thus suggest including "AUTOCOMPLETE = false" ...
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4answers
1k views

Preventing insecure webapp on subdomain compromise security of main webapp

I want your help on getting more concrete information on a type of vulnerability that I remember vaguely. I vaguely remember hearing about a year ago that if you set up a webapp on a subdomain, and ...
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2answers
614 views

Recent Facebook XSS exploit details

There was a recent XSS exploit on Facebook that posted a vulgar message and got users to click on a link to spread the payload. What vulnerability was exploited, and what can other sites do to avoid a ...
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2answers
3k views

Is doing credit card transaction via 3G secure?

3G, GPRS or other mobile-based connection. Because it seems like it's easier to intercept, than, say, land-based connection or encrypted WiFi. If it matters, the transaction I want to perform is ...
8
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3answers
346 views

Verify a website user is behind corporate firewall?

We have a public ecommerce website hosted at our datacenter onsite. For people who are within the corporate firewall hitting the website I want to display profiling information about the request of ...
8
votes
2answers
2k views

PHP - How to do safe input filtering in the light of multibyte encoding vulnerabilities?

For days now I try to get my head round how to write a secure web application in php, and it turns out to be particularly difficult. The more I read, the more I sink in deep swamps full of ...
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5answers
2k views

Websites that interactively test browser security (XSS, CSRF, Javascript, etc)

I'm looking for a comprehensive list of browser test sites so that I can visually prove that the browser is patched and configured for safe web browsing. My intent is to know what risks may exist ...
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2answers
1k 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 ...
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2answers
941 views

Slowloris attack?

Could someone analyze this info? We got information that slowloris attack took place. They say (hosting stuff) they have implemented mod_antiloris, is that enough btw? Feel free to share your opinion ...
8
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1answer
266 views

Is it dangerous “Powered by…” tag

Is it dangerous from a security perspective to put a line at the bottom of a website "Powered by Wordpress/Drupal/Django/WHATEVER" ? I know that certain platforms/applications have different security ...
8
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3answers
2k views

Encrypting user data using password and forgot my password

I am planning to do a web application which stores a lot of personal stuff (info, photos...). And to give users a sense of protection, I want to encrypt the data before storing it to the database. ...
8
votes
3answers
2k 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 ...
8
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2answers
1k views

What unique risks does MVC model binding bring to a website? What additional vigilance is needed?

From what I understand, "model binding" is where a website based on ASP.NET MVC or Ruby on Rails (there are others...) takes parameters in HTTP's GET statement and passes them as variables to code ...
8
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1answer
1k views

How to use postMessage securely

postMessage is a primitive introduced in HTML5 that web pages can use for cross-origin communication. What do I need to do to use postMessage securely? What are the primary security pitfalls or ...
8
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2answers
2k views

Is it possible to do HTTP header injection if CR/LF are stripped?

In HTTP response there is the following header with attacker controlled content: Content-Disposition:attachment; filename="attacker_controlled.html" The only characters that can't appear in ...
8
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2answers
599 views

Security issues with PHP Sandbox

I am working on a PHP sandbox for a Web Application Honeypot. The PHP sandbox will analyze a PHP file that may have been injected as part of an RFI attack. It should run the file in a safe environment ...
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3answers
1k views

Is a mobile app more secure for mobile use than the “normal” website?

An untrained end user who uses a mobile web browser is vulnerable to phishing and can't easily verify the the authenticity (or security) of a website among other issues. Also, it is very easy to ...
8
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1answer
581 views

Are browser still vulnerable to Cross-Site Cooking?

The latest article that I have been able to find about Cross-Site cooking was stating that it was possible to set cookie on 2 dots top level domain such as .co.uk. The mechanism for preventing ...
8
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1answer
350 views

I've discovered a vulnerability which can reveal personal information for multiple websites. How to go about it?

It's not so much a technical vulnerability, but rather a sloppy security practice by a web design consultancy. They use a CMS which they've augmented with an admin login. As it happens, the admin ...