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

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11
votes
4answers
619 views

Should a web application return true http errors?

Exception and error information can be used by a malicious user to map out the API of an web application, so it is routine to see security checklists to advise returning only a "Please contact your ...
11
votes
6answers
2k views

Ads appearing in our application when they should not be

I received a strange issue reported by one of my web application users. Apparently they are getting "ads" within the browser window when using my application. I didn't add advertisements at all. It's ...
11
votes
1answer
2k views

Properly masking credit cards

I'm wondering if the following masking of credit card would be considered PCI compliant. ######??????#### # Is plaintext ? is redacted Expiration date is available in plaintext Is it ...
11
votes
4answers
6k views

User name enumeration?

From what I understand it is bad security practice to display informative failed login messages like: The email you entered does not exist Instead of Incorrect email/password combination ...
11
votes
7answers
2k views

IP address black list

My website has a black list of IP addresses. The web application, in some way, detects all invalid, suspicious influences to it and remembers IP address and denies any requests from that IP address. ...
11
votes
3answers
1k views

What security measures should be taken when running a Linux web server out of our office?

I am interested in running our company's web server from our local office. The office makes use of file sharing and NAS devices among other common office protocols. The worst case scenarios I've ...
11
votes
2answers
11k views

Implications of Trace/Track Methods on Apache

When performing vulnerability scans using Nessus, against a host running Apache, one expected result is always "HTTP TRACE / TRACK Methods Allowed". While this result only has a base CVSS of 4.3, I ...
11
votes
4answers
2k views

How dangerous is it to store password in plain text on sites like GitHub?

I have a few private repositories set up on GitHub for some of the projects I am working on for my company. These applications connect to databases and I have database authentication credentials ...
11
votes
2answers
8k 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 ...
11
votes
2answers
907 views

Is allowing unfiltered curl request from a website a vulnerability?

Recently I was on a website which provided some non-sense feature: Enter a URL Press enter HTML source of a given URL is displayed It basically fetched a URL and just dumped the contents of it. ...
11
votes
2answers
6k views

What can an attacker do with a stolen SSL private key? What should the web admin do?

What can an attacker do with a stolen website certificate and key? What should the website admin do upon learning this?
11
votes
3answers
3k views

What is the next step of this file upload attack?

Yesterday I discovered somebody had uploaded this PHP code to my server as a .jpg file via my asp.net MVC application's "Upload your profile picture" form. I believe the attack was unsuccessful for a ...
11
votes
3answers
860 views

Is Gmail showing images by default a good idea for privacy?

Google have decided to show images in Gmail messages accessed via the web, iOS and Android by default: Instead of serving images directly from their original external host servers, Gmail will now ...
11
votes
3answers
1k views

How much information about the reason for an unsuccessful login should a web application give?

After an unsuccessful login attempt, should I inform the user about its reason? Or more generally, how much information about the reason for an unsuccessful login attempt should a web application give?...
11
votes
1answer
571 views

Public XSLT & XML playground (with PHP DOMDocument, etc.) Security Risks?

Let's say I want to set up a sandbox or playground in PHP that users can use to create (or paste in) XML and XSLT, then transform the XML via the XSLT (by means of PHP 5's DOMDocument and related ...
11
votes
1answer
2k views

How is time-based SQL injection different from other types of SQL injection?

I understand what a time-based SQL injection is, and I understand how it works (at least how it's detected/exploited). However, is there anything in specific which makes this type of injection any ...
11
votes
2answers
1k views

Security quiz for developers

Does anyone know of a short security quiz that could be administered online, to test the security knowledge of a developer? I'm looking for something simple to administer and simple to grade, ideally ...
11
votes
4answers
4k views

What is the right way of storing database connection strings from the security point of view?

What are recommendations, best practices and have-to-dos regarding handling connection strings in web applications? What things one should never, ever do?
11
votes
2answers
243 views

Using certificates to secure

I'm working on an application that comprises of a C# WebAPI (on Azure Websites) and a native mobile app. Essentially, a client creates a series of messages using a Web interface and these can be ...
11
votes
1answer
834 views

Webapp2 security

I am coding a REST web application that runs on Google App Engine, it authenticates API requests to privileged data using sessions by cookies provided by webapp2_extras.auth and webapp2_extras....
10
votes
3answers
8k views

How secure are sha256 + salt hashes for password storage [duplicate]

I started reading about password hashing recently on multiple sites like this page on crackstation and others, and for what I have understood, I should avoid using hashing algorithms like md5 and sha1 ...
10
votes
6answers
639 views

What are web attacks which users can run code on your servers?

I hear stories about insecure web servers and sites which people (or bots) break into and execute their own code on the server. My question is how is that possible? I heard of people putting their ...
10
votes
6answers
4k views

Security review: “HTTP header user-agent has been set to (something)”

We got a security review done of our PHP code and they team advised this in their report (amongst other things): /appdir/ Details The HTTP header user-agent has been set to \" . Request GET /...
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 ...
10
votes
4answers
17k views

Best place to store authentication tokens client side

When my users are authenticated they receive an authentication token, I need to use this authentication token to authorize some asp.net WebAPI calls. To do this I need to add the token to the head of ...
10
votes
4answers
591 views

Does my UI need to be secure if my API is?

I'm working on a project that is creating two new, separate web modules (possibly even on different servers) to support a new web application, with one serving up a static JS-based UI and the other ...
10
votes
6answers
11k views

Why is php not used for banking sites or for a banking transaction?

Other programming languages popular on the web, such as Java and .NET, are used for banking sites. However, I've rarely (if ever) seen a PHP application designed to be deployed for a banking site. ...
10
votes
4answers
536 views

When changing a password using a WebPage, must the old password be entered on the same screen?

There is a convention to always prompt for the old password on the same page as the one where the old password is being changed as shown below. Is it acceptable from a security perspective to allow a ...
10
votes
4answers
38k views

Why Do we Need CAPTCHA? In what case we should use it?

In what case we should implement Captcha based security?. How accurate it is and if there exists any alternatives for Captcha based Security.
10
votes
2answers
1k 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 ...
10
votes
3answers
602 views

What simple security considerations can I / should I make for a read-only API?

Right now I'm setting up an API, to be consumed on the client-side to set up a directory site. I'm wondering what extra steps I need to take just to prevent people from gaining write access to the ...
10
votes
3answers
11k views

Is it possible to inject HTML into image to provoke XSS?

Some answers mention that it's possible to inject attacker-controlled HTML into images and therefore provoke XSS. I guess that this HTML will be processed by browser only if hole exists in browser. ...
10
votes
3answers
3k 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 ...
10
votes
3answers
508 views

Should I ask a user to re-authenticate if the browser thumbprint changes? Is a server side library available?

Is there a security benefit to using the browser's thumbprint in addition to a session identifier to identify a unique session? Would it then be advisable to ask the user to reauthenticate (or simply ...
10
votes
2answers
1k views

What are the SQL-injections issues of parameterized queries?

I've written some code to generate an SQL query in ASP classic. I'm not sure if it's secure or not: Set adoCon = Server.CreateObject("ADODB.Connection") adoCon.Open "Provider=Microsoft.Jet.OLEDB.4.0; ...
10
votes
5answers
6k 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?
10
votes
4answers
2k 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 instance,...
10
votes
2answers
688 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 ...
10
votes
3answers
732 views

What security features should be present in every web-based CMS?

What are the most important security features that a web-based CMS should offer? What's vital? What would be nice to have? What features should the CMS not attempt to do? Please note: I'm looking ...
10
votes
4answers
433 views

What are the drawbacks of login request throttling?

In a web application, one way to protect against password guessing attacks is to lock out accounts after a set number of failed logins. This could be done on both source IP address and username. For ...
10
votes
3answers
8k views

CSRF cookie vs session based tokens

I will generate a CSRF token and include it in a hidden form field. When receiving the request, I will check the form value against the value either stored in the user's session or in a cookie. Is it ...
10
votes
1answer
3k 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 ...
10
votes
3answers
1k views

If I am obliged to store a password/certificate on a client side, how can i make sure that it is protected?

In certain cases we need to establish a key/password/certificate as a first timer and then as a client we need to use this key/password/certificate to get authenticated. Therefore the key/password/...
10
votes
4answers
9k 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 ...
10
votes
1answer
416 views

Is there a web application firewall equivalent of virustotal?

I'm wondering if there is a web application firewall (WAF) equivalent of VirusTotal? A site where I can throw for example injection strings, exploits or xss, and it will tell me what the default ...
10
votes
2answers
3k views

How to protect against clickjacking attack but allow legit iframes?

I'm aware of modern anti-clickjacking approaches, such as X-Frame-Options header or framekiller scripts. But all these tactics prevent content to be inside iframe. But what if there is a requirement ...
10
votes
3answers
2k views

How to perform penetration testing on a Flex application?

Possible Duplicate: What tools are there to inspect Flash SWF files? I have decompiled it, verified the source. All seems fine. Appscan also is not able to find anything in this case. But I ...
10
votes
1answer
3k views

Does it make sense to implement OAuth when no 3rd party is involved

I own a REST API at server side and a distinct web application that would call those APIs. I want to secure my APIs calls. After some reading, I want to implement the OAuth 1.0a mechanism at server ...
9
votes
7answers
5k views

Why does XSS affect so many websites?

According to an article I read 65% of all websites globally suffer from XSS. Why can't developers find and fix it? Please help me understand. I'm not from a security or tech background.
9
votes
6answers
2k 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 ...