The common name for the language used primarily for scripting in web browsers. It is not related to the Java language. Standardized as ECMAScript, its dialects/implementations include JavaScript and JScript.

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9
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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 ...
9
votes
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 ...
9
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2answers
2k views

Cordova/Phonegap: RefreshToken in localstorage

I am (partly) following a tutorial to develop a cordova app, based on angularJS. The author stores the refresh token in local storage, which was said to be very bad practice in one of the comments on ...
8
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4answers
667 views

Session Hijacked in case javascript blocked [closed]

If I blocked Javascript to be executed. Then what are the ways by which XSS can occur and what are possible threats in case of intranet application.
8
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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 ...
8
votes
3answers
200 views

Preventing user supplied javascript from posting to external server

I am writing an internal tool that will support plugins written by other developers. Ideally, these plugins would have a Javascript component to allow people to make widgets. Some of the pages these ...
8
votes
5answers
345 views

Is it a risk to highlight text while reading a webpage?

Whenever a user selects or highlights text on a webpage, an OnClick() event is generated. Some of the web browser security models depends on explicit end user interaction, such as OnClick(), before a ...
8
votes
1answer
5k views

Iframe javascript Keylogger

Is it possible for a website to have a javascript keylogger and also contain an iframe that goes to a "client" site. Can the the JS log all key strokes done on the client site? Can the (host) iframe ...
7
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3answers
1k views

How serious are XSS attacks

A website I visit allows this kind of attack, to be implemented with GET in the URL <SCRIPT SRC=http://ha.ckers.org/xss.js></SCRIPT> Along with many others on this page: ...
7
votes
4answers
2k views

Escaping JavaScript constants

how can untrusted values be included in a html-page as javascript string constants? Although the case i am asking uses JSF and Rails, I think this is a general problem independent of the server side ...
7
votes
4answers
839 views

Security attacks on PHP web applications

I know about following security attacks on php applications (html,php,js). XSS SQL Injection CSFR Session Hijacking /Fixation Code Injection Remote file injection Should i know about any other or ...
7
votes
1answer
2k views

What possible use does an iFrame have for security?

I'm looking at code for an old login form I'm redesigning. It's a simple table with two input fields for username and password. But just before the end </table> tag there's a blank iFrame which ...
7
votes
2answers
18k views

Javascript and jQuery not secure over https

I am building an ASP.NET MVC 3 app which will run in Azure. Everything was working well, until I switched to https. Now most of my jQuery plugins and some other javascript are not secure. I'm using ...
7
votes
4answers
290 views

Limited JavaScript app scenario: Attack vectors and mitigation

I'm going to be developing a single page JavaScript app which allows input via a textarea. This input is never sent to the server, never shown to another user, and will only be persisted in browser ...
7
votes
2answers
550 views

Best practices for integrating external javascript?

I'm looking for some standard pieces of advice on how to integrate external JavaScript into a website. For example, on mywebsite.com: <script ...
7
votes
1answer
68 views

Unlock codes for a mobile app

This is for an Android (via Cordova/Phonegap) game project. My goal is to be able to provide a "promo code" that will allow anyone to unlock the game for free, but I want to limit each code to only ...
7
votes
1answer
646 views

Child iFrame hash verification of parent iFrame content

Consider the following scenario: Alice wishes to browse Victor's website while on the job at Initech. Victor's website is hosted on an alternative domain name system to which Initech's DNS does not ...
6
votes
5answers
10k views

Hiding JavaScript source code

In a web-app should one strive to hide as much of the code as possible, for example from view source? In particular I was wondering should JavaScript be hidden, especially ones used for Ajax? I was ...
6
votes
3answers
1k views

What's wrong with my own authentication scheme?

So I want to write my own authentication scheme for a web-app server, as follows. I assume this is a Bad Idea from either security or cost-effectiveness reasons and I know the conventional wisdom is ...
6
votes
5answers
6k views

Obfuscating JavaScript code

Some Flash developers are afraid of JavaScript. Their point of view: Stealing JS source code is effortless, one would just 'view source' and copy it. Yes, you can decompile Flash bytecode, however it ...
6
votes
3answers
961 views

How secure are self decrypting HTML files for data storage?

I recently came across a JavaScript self decrypting archive. Is it secure enough to be used as a portable password storage tool? The author has even challenged it to be cracked.
6
votes
5answers
22k views

Playing with Referrer Header

There are 2 sites: http://www.site1.com http://www.site2.com http://www.site1.com contains link to http://www.site2.com as <a href="http://www.site2.com/">link<a/> When user clicks ...
6
votes
3answers
9k views

Secure jquery ajax calls from a non secure page

I could not find a clear answer, but if I have the following situation: I browse to a page let's say http://www.example.com/index.html Now I use a form on this page to do a postback with jquery's ...
6
votes
1answer
713 views

Access to other local files from a local HTML file

I tried this question on programmers site with no luck Do you see any reason to block a local html file from accessing another local files located in the same folder? I mean, if a user downloaded an ...
6
votes
4answers
418 views

Is flash or javascript a bigger security concern?

Many flash website whitelisting extensions for chrome (such as flashblock and flashcontrol) use javascript in order to selectively block Adobe Flash from functioning. Thus, In order to get this ...
6
votes
3answers
491 views

Are there any tools to detect JavaScript-based WCF/AJAX calls?

I'd like to determine if a given JavaScript contains the logic to make a AJAX/WCF call, or determine if one is being executed at runtime. Does anything like this exist?
6
votes
3answers
435 views

Favicon Redirection Possible Security Flaw

I have the domain example.com When I enter the URL https://api.example.com, Chrome loads the page and also tries to load https://myapp.example.com/favicon.ico, and that request receives a 301 ...
5
votes
1answer
5k views

Is this jQuery ajax call vulnerable to XSS?

If somebody can edit $("#field").val(), can they change the url property here to point to another location? $.ajax({ url: "http://mywebsite/script?param=" + $("#field").val(), dataType: "jsonp", ...
5
votes
3answers
438 views

Are CSRF Attacks Really Blind

I'm new to CSRF attacks but don't see how they are always blind. Let's say we are dealing with a site where the asset we need to protect is the HTTP response. Something like one's medical history. ...
5
votes
2answers
1k views

Web & insecure HTTP - Using RSA for encrypting passwords on the client side

I used client side password hashing in my register and login project. Its purpose is to prevent passive adversaries/eavesdroppers from discovering users' plaintext passwords when HTTP requests are in ...
5
votes
2answers
1k views

Is a JavaScript implementation of AES any less secure than other language implementations?

There are a few JavaScript AES implementations available such as Gibberish-aes So assuming the AES algorithm has been implemented correctly in this library then it should be as secure as any other ...
5
votes
2answers
1k views

Is it possible to create a secure chat web application relying on HTML5 web sockets?

Is it possible to create a secure chat web application using just HTML5 and Javascript? What possible security holes would there be if the server doesn't store the messages, just relay them using ...
5
votes
4answers
669 views

Is JavaScript self-injection dangerous?

I have a toy web application that can be described roughly as a per-user key-value store. After logging in, the user can view and modify her set of key-value pairs. The keys and values are stored in a ...
5
votes
3answers
1k views

What authentication system (OpenID, Facebook, etc) permits Javascript-free and/or Cookie-Free operation?

I'm looking for an authentication system that relies on 3rd parties (ADFS, OpenID, SAML) but doesn't rely on cookies or Javascript... or at least can make them optional. My intent is to gracefully ...
5
votes
2answers
7k views

DOM Based XSS attacks: what is the most dangerous example?

I knew that XSS attacks (“non-persistent” and “persistent”) can hijack user session, deface websites, conduct phishing attack, etc. However, I can't understand what is dangerous of DOM Based XSS if ...
5
votes
3answers
559 views

What are NoScript surrogates and should one disable them for more privacy in browsing?

NoScript has a feature of supplying its own "surrogate" scripts instead of well-known tracking/ad scripts (Google Analytics, for one). Does it matter for my privacy if I do not change the factory ...
5
votes
2answers
2k views

Risks of client-side encryption using Stanford Crypto Library

I'm building a simple web application for encrypted chat. Each message will undergo 256-bit AES encryption on the client side, using the Stanford Javascript Crypto Library. No unencrypted data or ...
5
votes
2answers
163 views

User entered Javascript security implications

I'm creating a web site that lets people create their own site using a subdomain. Are there any security implications by letting people add custom javascript to their pages? If so, which ones? XSS? ...
5
votes
3answers
5k views

Javascript Malware: How does it work, and how can it be mitigated?

I am wondering how malware gets served through Javascript. I've noticed a few illegitimate pop-ups while visiting some financial websites. I wonder how malware exploits work against the application ...
5
votes
1answer
146 views

Is it safe to allow untrusted field names in JSON?

When forming a JSON data structure, are there any security risks with allowing the field names to be chosen by an attacker? You can assume they'll be quoted properly. I'd like to know if allowing ...
5
votes
2answers
140 views

Protection against synthetic queries

Note: One, I am not sure if synthetic queries is right word for the risk I am talking about. Second, though I am considering 3-tier model of web-applications general answers are welcome in ...
5
votes
2answers
582 views

How to ensure that files uploaded by users do not contain any XSS code

I have been working on providing the security related to the XSS attacks. My website only allows following mime-types: XML, CSV, HTML, PLAIN, VND_WAP_WML, APPLICATION_ZIP, APPLICATION_PDF, ...
5
votes
1answer
416 views

Using javascript, is it possible to iterate through all cookies saved in the user browser and send them to me?

Again, I am new to the programming and security world. I should mention that it is just a theoretical question so I can anticipate this kind of attack. Using javascript, is it possible to iterate ...
5
votes
3answers
460 views

Secure a publicly accessible REST api

We're building a public single page app in JavaScript that talks to a back-end REST service. What we want is for that REST-service to be only accessible from the single page app. Since it's a public ...
5
votes
2answers
299 views

Do Javascript malware signatures exist?

Are there signatures for malicious JavaScript codes as they exist for other viruses/worms/trojans developed in other programming languages ? If so, are these javascript malware signatures defined ...
5
votes
2answers
829 views

Is it safe to use createHTMLDocument to sanitize HTML?

i'm wondering how safe it is to use createHTMLDocument to do HTML sanitization. I've tried to implement it like this: function sanitize(string) { var elm = ...
5
votes
1answer
1k views

XSS JavaScript Double Quoted String with HTML Escaped Possible?

Is it possible to inject XSS in a JavaScript variable if a website inserts HTML encoded, user input in a double quoted string? var userString = "perfectly &quot;safe&quot; input from user?";
5
votes
2answers
2k views

Problems with avoiding JSON hijacking with MVC3's AntiForgeryToken, or similar token validation

I'm hesitant to implement the proposed anti-JSON hijacking solutions since The recommended solutions to mitigating JSON hijacking involve non-REST-full JSON POSTs to GET data The alternate ...
5
votes
1answer
325 views

Exploit SoakSoak injected in Wordpress

I have recently received an attack to my website and Google is warning visitors to not load the page. The malware is located in wp-includes/js/swfobject.js of my Wordpress and I had deleted it but ...
5
votes
1answer
936 views

How should I mitigate the XSS vulnerabilities in KnockoutJS described at mustache-security?

The site Mustache-Security describes XSS vulnerabilities in KnockoutJS... The vulnerabilities come from the use of eval (or some equivalent) to convert text in the data-bind attribute to executable ...