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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2
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2answers
2k views

Are HTTPOnly Cookies submitted via XmlHTTPRequest with withCredentials=True?

I have a two part question here. I have a javascript webapp accessing privileged REST endpoints. I would like to protect against CSRF. Currently, I have a login system built which returns a login ...
3
votes
3answers
1k views

RSA Key Pair generation with Javascript

I need to generate a RSA key pair with Javascript. This key pair will be used for encrypting a one time blob of data (20-100kb), then discarded. This data can be reduced to a couple of hundred kb or ...
5
votes
2answers
984 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 = ...
1
vote
1answer
220 views

If CORS is set to * your browser can't read the response if cookies are sent over. Why is the wildcard considered insecure? [duplicate]

If this header is set Access-Control-Allow-Origin: * javascript can make a request to the domain and read the response if and only if no cookies are sent over, otherwise the javascript cannot read ...
15
votes
3answers
7k views

What does this javascript file do? Is this a virus?

While searching on Google I found a website that shows one set of content to the Google Bot and an other to users (by redirecting to a new domain), and also a very suspicious Javascript file. Maybe ...
2
votes
1answer
453 views

encodeURIComponent in a unquoted HTML attribute

My gut feeling is that the following should be attackable: $("<td><a href=somefile.php?url="+encodeURIComponent(somevar)+">Download Here</a></td>"); In contrast to ...
1
vote
2answers
307 views

Online Shopping password keylogger risk

Suppose I do an online shopping they are asking me to enter my card details like four digit number(whatever related to that) and they are asking me to enter the PIN number too. If I enter all this ...
2
votes
1answer
185 views

How does this website prevent directing away from it

I'm using the latest version of Firefox with Ghostery and Adblock plus installed. This website somehow prevents navigation away from it. How does it do this and how can it be protected against? I ...
1
vote
1answer
339 views

Can location.pathname lead to XSS?

<div id="cat"></div> <script> $("#cat").html(location.pathname); </script> I think that example would work, but anyway, if location.pathname has to be a valid page, can this ...
4
votes
2answers
622 views

Safety of using web based proxy?

Lets say for example I have to use a public online proxy like https://www.zend2.com to load a PHP webpage controlled by me containing sensitive data over HTTPS. How would I make sure that the proxy ...
5
votes
2answers
355 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 ...
1
vote
1answer
188 views

Could I XSS a page that filters &,",< and > characters and has Content-Type set to UTF-8?

I am trying to pentest a dummy website that has a form with a TEXTAREA input on one page. When the form is submitted, the contents of the form are displayed on a second page. However, the second page ...
9
votes
1answer
592 views

XSS Technique - & JavaScript Include

I was looking through the OWASP XSS Filter Evasion Cheat Sheet, and there was one technique that was completely new to me: & JavaScript includes <BR SIZE="&{alert('XSS')}"> I ...
5
votes
2answers
8k 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
4answers
692 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
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 ...
2
votes
2answers
173 views

Securing a Shuffle Algorithm

After reading about writing a secure shuffle algorithm, I realized that my module that generates a password is only as strong as my PRNG, which in this case is Math.random(). I'm confused as to how to ...
-3
votes
1answer
108 views

Is it fine to run custom javascript on a site? [closed]

I have been running alot of javascript code on nike.com through the console in order to create a shoe bot. The code i paste into the console has one intense loop with many iterations which makes me ...
1
vote
2answers
204 views

How can one find keyloggers in javascript?

Assuming no XSS and a client-side only page, how can a keylogger be identified in javascript code? Should I simply look for the id of the targeted fields and possibly some sort of DOM traversal to ...
4
votes
2answers
2k views

Could a malicious JS file pointed on URL/URI attack the browser/computer?

I found some website blacklisted on Google. I mean when you try to visit them, you get something like shown on this picture: After a small search, I found that some of them have a malicious ...
1
vote
3answers
2k views

Is JavaScript malware as dangerous as native viruses? [closed]

Can JavaScript malware be as dangerous and damaging as more traditional viruses that are programmed mostly in native APIs?
1
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2answers
220 views

Want to build a password manager using OpenPGP.js

I'm kind of tired of the password managers that are available around... I need one that's open source, that works on OSX, that lets me store .pem files and that I can trust. As I haven't found one, I ...
120
votes
3answers
16k views

This JavaScript code is injected on my hotel Wi-Fi: should I be worried?

While connected to my hotel Wi-Fi, visiting the URL http://www.google-analytics.com/ga.js results in the following content being served: var ga_exists; if(!ga_exists) { ga_exists = 1; var ...
1
vote
5answers
448 views

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

I'm trying to make a file uploader using PrimeFaces, but it is vulnerable to scripts: If someone tries to upload a file (e.g. a résumé) that includes JavaScript, this could get executed once the file ...
1
vote
1answer
85 views

Detecting code source variants of the same function [closed]

Suppose I have this JavaScript malicious function f1() : <SCRIPT type="text/javascript"> function f1(){ a=1; b=2; c=a+b; } </SCRIPT> This function is embedded within a larger ...
1
vote
1answer
158 views

Is it safe to call an untrusted service with jquery.ajax and dataType 'jsonp'

From what I understand, the JSON-P technique generates a script tag into the DOM of an HTML page to get across the single-origin restrictions imposed on the XMLHttpRequest JavaScript API for AJAX ...
2
votes
1answer
2k views

javascript:alert(“test”); command does not work

Hello! As I have done before and also have read in many web sites, that just simply writing: javascript:alert(document.cookie); should work on any web page. But now, I was not able to execute it. I ...
3
votes
1answer
368 views

XSS - history stealing

I am little confused about this matter. By simply writing a JavaScript code we can go through our browser history and identify visited links. It is fine. But how an attacker use this to identify a ...
2
votes
1answer
206 views

JavaScript code authenticity when loaded from 3rd party website

Background A discussion about not sourcing JavaScript files from other websites (http://www.reddit.com/r/netsec/comments/29hfhz/please_dont_use_externally_hosted_javascript/) got me thinking. ...
2
votes
1answer
172 views

Sandboxing user input html

I want to render user uploaded HTML (consisting of possibly many files with images, custom css, custom js, all uploaded in a zip file) for preview purpose. The user that submits the html will be the ...
-1
votes
1answer
899 views

How to recognize if someone using password Reminder Script [closed]

I have been trying to know what these so called Gmail hacking scripts actually does (just studying for some knowledge purpose) and one of such scripts is this, which seems beyond my knowledge: ...
1
vote
0answers
141 views

XSS Vectors for new Image()

What are possible XSS vectors to this JavaScript code new Image().src = encodeURI('[user url here]'); Let's assume two cases: [user url here] is some string provided by user (with no validation) ...
3
votes
4answers
734 views

How is this XSS attack working?

SPOILER ALERT: This question contains an answer to one of the problems from the Google's XSS Challenge! Please stop reading further if you're not interested in knowing the answer right now. I'm ...
2
votes
3answers
223 views

XSS prevention by black-listing

I have a reflected XSS vulnerability in my Web application. I have decided to take the black-list approach instead of the popular white-list approach. My question is can there exist a malicious ...
2
votes
2answers
979 views

XSS in HTML meta tag

There is a web application which contains a search function. When I search for aaaaaaaaxss I get this: <meta property="the:property" content="100 Results for aaaaaaaaxss (Page 1)" /> It strips ...
2
votes
1answer
1k views

HMAC secret key client storage

I've read numerous articles about using HMAC and the secret key for client authentication in a RESTful client (Javascript) application today. Still, I don't find a single source that is able to ...
2
votes
1answer
227 views

Should a space in a password count as a symbol when checking for complexity?

There is no doubt in my mind that spaces should be allowed in passwords. I see some websites disallow spaces, symbols in passwords and even enforce minimum length which seems t otally nonsensical to ...
0
votes
1answer
954 views

How do I inject JavaScript into a JPG image and execute it when uploaded?

I've recently joined a security project, and received a task to demonstrate the risk related to an end-user uploading an image containing embedded (malicious) JavaScript code. I used EXIFeditor to ...
5
votes
3answers
703 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
1answer
1k views

Is 'Forge' Javascript crypto library secure? [closed]

I need a client-side crypto library. I've seen https://github.com/digitalbazaar/forge linked many times on stackexchange. Forge seems to be the most complete and well-documented crypto library for JS. ...
3
votes
1answer
243 views

Javascript client side image decryption, does this add any safety or is it flawed

I want to store passport copies safely in a database, the database itself is a normal MySQL database and on a somewhat trusted web server. The user who owns the passport copy should only be able to ...
0
votes
1answer
162 views

Access-Control-Allow-Origin possible threats on static JS file

As I am working on a research, I need allow users to read my JavaScript file using Ajax. However, I want to make sure about consequences of adding Access-Control-Allow-Origin header for just this ...
0
votes
2answers
416 views

How dangerous javascripts really are? [closed]

I've watched this video, and what this guy says is that with javascript its easy to create a worm that steals your information also that javascript will continue to execute even tho you closed the tab ...
0
votes
1answer
319 views

Can I use crypto.getRandomValues to create a private key?

In the window.crypto spec: http://www.w3.org/TR/WebCryptoAPI/#RandomSource-interface It says explicitly: "Do not generate keys using the getRandomValues method. Use the generateKey method ...
1
vote
1answer
163 views

Securing Javascript plugin

My company offers a Javascript plugin that is meant to be embedded with websites. It works in a similar fashion to Google Analytics, in which you add a bit of Javascript and then it does some magic on ...
0
votes
1answer
435 views

JS malware detection

Is there a way to detect a malicious JavaScript code within a webpage before the script runs on my computer ? I want to develop a Python script that prevents from 8 JS malwares that I can embed on my ...
1
vote
2answers
216 views

If I change any character in a private PEM, should the public PEM be different?

I'm generating a public PEM-format key from a private PEM-format key. I noticed that if I change a few characters near the end of the private PEM that the public PEM generated from the modified ...
-2
votes
1answer
457 views

How to decrypt javascript code extracted from PDF

I analyzed PDF, and extract javascript code. But javascript code is encrypted. I can't decrypt it. Please advise me. javascript code ...
1
vote
1answer
1k views

Is it safe to use localstorage to store session variables and user password? [closed]

I'm trying to make a web application in Java with a login/session system using com.sun.net.httpserver and as far I know, it does not have an inbuilt method to this. So, I had the following idea: 1 - ...
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 ...