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

learn more… | top users | synonyms

78
votes
8answers
5k views

Do we need to logout of webapps?

A quick Google search doesn't reveal whether it is important to logout of webapps (online banking, Amazon, Facebook, etc.), or if I am safe just closing the tab or browser. I am sure I heard on some ...
73
votes
2answers
36k views

What is the difference between https://google.com and https://encrypted.google.com?

Is it there any difference between the encrypted Google search (at https://encrypted.google.com) and the ordinary HTTPS Google search (at https://google.com)? In terms of security what were the ...
66
votes
15answers
6k views

Does an established ssl connection mean a line is really secure

From the view of somebody offering a webapplication. When somebody connects with SSL (https) to our service and submits the correct authentication data, is it safe to transmit all sensitive data over ...
60
votes
3answers
7k views

Is a rand from /dev/urandom secure for a login key?

Lets say I want to cookie for a user, would simply going to /dev/urandom, generating a 1024 bit string, checking if it already exists (and looping till I get a unique one) suffice? Or should I be ...
59
votes
8answers
6k views

Can anyone provide references for implementing web application self password reset mechanisms properly?

We are implementing self password reset on a web application, and I know how I want to do it (email time limited password reset URL to users pre-registered email address). My problem is that I ...
58
votes
10answers
17k views

Bad practice to have a “god” password?

Is it bad security practice to have a password that will allow you to access any user account on a website for support purposes? The password would be stored in a secure manner and would be super ...
58
votes
6answers
6k views

Can anybody explain XSS?

I work programming Enterprise Java applications and do very little web development in 2002. I'm interested in security and like to read articles about it. However, I never fully understand how XSS ...
55
votes
10answers
4k views

Does disabling right click have any impact on security?

On a banking website I see that they have disabled right-click. Does that make the site any more secure? Is it a good general practice?
54
votes
7answers
21k views

Is BASIC-Auth secure if done over HTTPS?

I'm making a REST-API and it's straight forward to do BASIC auth login. Then let HTTPS secure the connection so the password is protected when the api is used. Can this be considered secure?
47
votes
6answers
9k views

SQL injection — but why isn't escape quotes safe anymore?

I haven't seen this question asked, and feel it's a valuable bit of information to have, especially because this is a huge source of mystery and confusion. Raw SQL When you're writing SQL -- for ...
46
votes
13answers
7k views

What are the pros and cons of site wide SSL (https)?

What are the pros and cons of encrypting all HTTP traffic for the whole site through SSL, as opposed to SSL on just the login page?
41
votes
7answers
2k views

Why is application crash considered insecure?

If an application crashes, the program stops and there is nothing anyone can do about it, other than starting the program again. Crash is a bad behaviour in general and should be avoided, but why are ...
41
votes
11answers
6k views

What to do about websites that store plain text passwords

I recently received an email from a popular graduate job web site (prospects.ac.uk) that I haven't used in a while suggesting I use a new feature. It contained both my username and password in plain ...
38
votes
9answers
6k views

I just discovered major security flaws in my web store?

A little background info here: I'm a self-taught web developer with very little experience outside of html/css, and the company I work for has hired a third party web development team to design us an ...
35
votes
15answers
5k views

Should we protect web application source code from being stolen by web hosts through obfuscation?

Is it worth to obfuscate a java web app source code so that the web host cannot make wrong use of the code or even steal your business? If so, how should this be dealt with? How should we obfuscate? ...
34
votes
6answers
2k views

Why is HTTPS not the default protocol?

Why is HTTP still commonly used, instead what I would believe much more secure HTTPS?
32
votes
5answers
4k views

How to Securely Implement a “Remember Me” Feature?

Assuming you already have a website that implements all of the standard login stuff, what is the correct and most secure way to allow users to automatically be logged in for a certain time period ...
30
votes
7answers
1k views

Dealing with excessive “Carding” attempts

We are currently setup using Magento on a LAMP stack for our e-commerce platform. As of a month or two ago we began noticing a lot of carding attempts against our website. All attempted transactions ...
29
votes
6answers
2k 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. ...
29
votes
5answers
4k views

Are GUIDs safe for one-time tokens?

I see a lot of sites use GUIDs for password resets, unsubscribe requests and other forms of unique identification. Presumably they are appealing because they are easy to generate, unique, ...
28
votes
2answers
5k views

Web Application encryption key management

In a nutshell, let's consider a web application which stores some information in a database as encrypted data. While I'm purposely trying to keep this some what generic, here are some assumptions: ...
27
votes
3answers
1k views

Is there a security reason for a site to limit the number of times a user can change their password?

Is there a security reason to disallow a user to change their password as frequently as they want? I have found this security policy in a site and I am not sure why it is enforcing it. One reason I ...
26
votes
3answers
6k views

What useful things can I do with the html5 “keygen” element?

There's a new* keygen element in the html5 spec. It's supported in major browsers excepting Internet Explorer and Safari. Here's what it looks like: <form action="processkey.cgi" method="post" ...
25
votes
9answers
1k views

Why do some people really hate security via client-side?

For instance, lets look at a common login system for a website HTTPS connection is made User submits credentials via POST Server-side code hashes the password and looks if it matches the user name ...
24
votes
4answers
2k views

Is it okay to reveal database's table names?

I'm developing web application that uses database. I have to do some operations which needs database table names and db table schema. Will it be secure if I send this kind of information to client ...
24
votes
5answers
12k views

Are there security issues with embedding an HTTPS iframe on an HTTP page?

I've seen websites placing HTTPS iframes on HTTP pages. Are there any security concerns with this? Is it secure to transmit private information like credit card details in such a scheme (where the ...
24
votes
8answers
4k views

Is anybody using client browser certificates?

Client browser certificates seem to be a nice way to protect sites from intruders - it is impossible to guess and should be harder to steal. Of course, they do not solve all the problems, but they add ...
23
votes
2answers
2k 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?
22
votes
2answers
6k views

Why is the same origin policy so important?

I can't really fully understand what same origin domain means. I know it means that when getting a resource from another domain (say a JS file) it will run from the context of the domain that serves ...
22
votes
5answers
3k views

Could mint.com be more secure, and if so, how?

After reading a bit about mint.com on the money stack exchange, I wanted to give it a try. But frankly, it scares me a little bit. The site has a bunch of links explaining how they're so secure. I ...
22
votes
4answers
542 views

How does using OpenID affect webapp security?

Using OpenID for authenticating users grows in popularity and, in fact, makes a webapp easier to use. But what are the security considerations one should bear in mind when deciding whether to ...
21
votes
5answers
1k views

How to improve as a security expert

I'm a professional software developer with a high interest in web application security. I'd say that I probably have a better understanding of the security of web applications than the average ...
21
votes
2answers
8k views

Minimum requrements for storing last 4 digits of credit card number?

We have a merchant website that uses Autorize.net's CIM and AIM. Our users may have multiple credit cards so we'd want to give them opportunity to distinguish between credit cards that they use on ...
21
votes
3answers
2k views

Pitfalls of using OAuth for mobile Applications

OAuth seems to be getting a lot of traction at the moment as an authorization solution for web applications and mobile applications. I'm interested in understanding what the pitfalls of using OAuth ...
20
votes
11answers
5k views

Prevent my site from being copied

Is it possible to protect my site from HTTrack Website Copier or any similar program? Without setting a max number of HTTP request from users.
20
votes
2answers
1k views

From a technical standpoint, how does the zero-day Internet Explorer vulnerability discovered in September 2012 work?

I'm looking for an answer that explains the issue from the prespective of a developer/engineer. What is exactly being exploited and why does it work? Please note that I am not looking for ...
20
votes
9answers
2k views

Is a web application firewall necessary if the application is secure?

Recently I've been reading about Web application firewalls and the fact that they protect against most frequent attacks like injections, XSS or CSRF. However, a good application should already be ...
20
votes
1answer
2k views

What cookie attacks are possible between computers in related DNS domains (*.example.com)?

Here, several servers in the same DNS domain emit cookies under a variety of settings (scope, HTTPS, Secure) and another host emits a cookie with the same value. Example Suppose a user has the ...
20
votes
7answers
1k views

If I include a Forgot Password service, then what's the point of using a password?

I've implemented a Forgot Password service in the following way: User goes to login page, clicks on "Forgot password?" User is presented with a form that asks for their email address. Email is sent ...
20
votes
7answers
768 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.
20
votes
3answers
5k views

How should web app developers defend against JSON hijacking?

What is the best defense against JSON hijacking? Can anyone enumerate the standard defenses, and explain their strengths and weaknesses? Here are some defenses that I've seen suggested: If the ...
19
votes
2answers
595 views

How is “<scrscriptipt>” or “selselectect” used to avoid filtering?

A technique for avoid filtering of common words is the one I described in the title. However, why does this technique work? SELECT isn't the same as SELSELECTECT for example.
19
votes
2answers
990 views

Do Simple Linux Servers Really Need a Non-Root User For Security Reasons?

Playing devil's advocate, Let's assume I purchase a Linux server from a hosting provider. I am given a password for the root user and am told I may login using SSH. The only purpose this server has ...
19
votes
4answers
1k views

How long should an e-mail address confirmation link last and why must it expire at all?

After a user registers an e-mail is sent to them with a link they must click on to activate the account. I know other sites have a limit on the amount of time the user has to click the link, else the ...
19
votes
5answers
2k views

Should I use Suhosin for PHP?

Suhosin can be used to increase the security of your php application. I can really see the use of it when you are using shared hosts, with multiple (possibly evil) people running their PHP apps ...
19
votes
4answers
1k views

Should websites be allowed to disable autocomplete on forms or fields?

Currently, there is an HTML form/input attribute called autocomplete, which, when set to off, disables autocomplete/autofill for that form or element. Some banks seem to use this to prevent password ...
19
votes
2answers
2k views

How do I use Markdown securely?

How do I use the Markdown library safely? What do I need to do to make sure that its output is safe to include into my web page? I want to allow untrusted users to enter content (in Markdown ...
19
votes
3answers
5k views

What are the best practices for hardening a php.ini file?

In order to secure a PHP installation, what are the best settings for a php.ini file? What is absolutely vital in terms of security? What is recommended for most use cases?
18
votes
14answers
2k views

How can you become a competent web application security expert without breaking the law?

This question was asked here on Programmers Exchange, but it was suggested I ask here as well since most of the experts would likely hang out on IT Security exchange instead. I find this to be ...
18
votes
6answers
2k views

Why do we ask for a user's existing password when changing their password?

In a web applications context, when a user wants to change their current password, generally they would have to enter their current password first. However at this point, the user has already been ...