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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523 views

Is this code harmful? Why?

Code: http://pastebin.com/kJ8ZGP82 That code gets retrived from http://ui.sidepage.co for every HTTP page I visit (not HTTPS) and load it into the body tag of the page. Is it harmful in any way? ...
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2answers
786 views

HTML Vulnerabilities

My question is three-fold. Background I was asked to do some vulnerability scans on a website with some holes (I think). On a particular page, I was able to escape the text field and write on the ...
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5answers
524 views

Is it possible to see if a script on a website steals session cookies?

I'm looking as some web analytics solutions, I know it sounds paranoid. but cookie-based web analytics need for you to paste their JavaScript code on your web-site. I don't like the idea too much of ...
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3answers
8k views

Why is JavaScript disabled in the Tor Browser Bundle?

Didn't Tor create a local socks proxy? Why doesn't all the Web traffic go over this local socks proxy and why is JavaScript disabled in the Tor Browser bundle? If you would connect with firefox for ...
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4answers
598 views

How can I constrain or limit 3rd party Javascript (*.js) files that can DOS my site?

Many website owners integrate Google analytics, various Facebook or Twitter social media javascript plug ins into their web pages. The problem is that this trust seems to be "all or nothing", meaning ...
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2answers
592 views

Why do I get AV alerts when browsing a web page?

I'm using the latest version of Firefox and Windows is up to date. When I was browsing a webpage and clicked a link the browser displayed "connection has been reset" and AVAST poped-up saying "Alert!" ...
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3answers
97 views

Any Security Risks for using mailto:?

I use a PHP script which performs a database search and when no result are found, user is presented with a mailto link with this format mailto:example@test.com?subject=SEARCHED_QUERY_HERE The ...
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3answers
182 views

Can a browser JavaScript console ever be an issue?

I'm sure most of you are familiar with the JavaScript-based game Candy Box. As you probably know, one can cheat this game's candy system by sending commands to the console. For instance, if you ...
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4answers
1k views

bot detection via browser fingerprinting

I've recently noticed that a few companies have begun to offer bot and scraping protection services based on the idea of browser fingerprinting to detect them, and then blocking the specific ...
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2answers
14k views

XSS cookie stealing without redirecting to another page

I'm practicing in VM following the OWASP guide. I know that is possible to steal the cookie by redirecting to "False" page etc. but I would like to steal the cookie without redirecting on another ...
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2answers
432 views

Exploiting flash XSS holes

I have a URL to a flash file. Sample :- http://abc.mydomain.com/Findme.swf Now, there is a parameter called xmlpath as :- http://abc.mydomain.com/Findme.swf?xmlPath=something. Is it not that ...
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2answers
488 views

Can a whitespace regex character be used to perform a javascript injection?

if I want to validate the input of a <textarea>, and want it to contain, for example, only numerical values, but even want to give users the possibility to insert new lines, I can selected ...
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2answers
62 views

Is it neccessary to use X-FRAME-OPTIONS to prevent ClickJacking attacks?

I use this Javascript Code, and it works perfectly: if (top.location != location) top.location.href = location.href Many researchers told me to not use this. Can any one bypass it? Are there ...
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2answers
284 views

Website infected with unwanted “redirections”, apparently via javascript code

I'm working on a clients website, and I realize they've been compromised. Early today there was a major problem with a php eval(base64_decode issue. That was cleaned up via Andy Stratton clean.php ...
3
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2answers
384 views

Injecting information in a web page (Gmail). Does it raise security problem?

I am developing a Google Chrome extension which encrypts/decrypts emails for Gmail users. So, I detect encrypted emails when the user opens an email on using tags. Once an encrypted email has been ...
3
votes
1answer
346 views

Security of Javascript in mobile browsers

Is Javascript on a mobile browser more secure than Javascript on other types of systems? For instance, if I have a site that includes some client-side (Javascript) encryption code, with the intention ...
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2answers
569 views

Implementing brute force attacks on hash values in Javascript

I'm working for my bachelor thesis at the end of which I aim to implement a proof-of-concept Javascript-based hash cracker. The idea is to work like this: Users can submit a hash value along with ...
3
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1answer
199 views

How does the same-origin policy apply between browser tabs? [duplicate]

Let's assume that we have 2 open tabs in a browser containing page A (A.html, A.js) into the first tab and page B (B.html, B.js) into the second tab and that page A and B have the same origin (scheme, ...
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2answers
917 views

SJCL : convert ascii to a BitArray & compute random numbers

I am using the Stanford Javascript Crypto library and i'd like more information about it. 1.) I have an ASCII text and a random 128-bit key. I want to concat those two things, so I convert the ASCII ...
3
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2answers
512 views

Should the Keygen element be used to create a certificate for mutual auth TLS? What alternatives are there?

I'm interested in using mutual auth TLS to improve the security of my javascript based webservices . I've looked at the Keygen element and given all its issues, not sure if this can even be used for ...
3
votes
1answer
255 views

Suspecious js file sent as email attachment

I received a js file with following code in my spam folder but I decided to take a look into the file. Do anybody of you know what does this code might do? var evl='';function nr() { evl = '}; ' + ...
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votes
2answers
91 views

Why browsers implement stricter policy for local files

I have a problem viewing HTML/JS/CSS files generated on disk. Specifically, several calls in javascript are blocked by Google Chrome. I googled and found an answer here: ...
3
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1answer
245 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 ...
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2answers
387 views

Is this password generator safe?

128-bit entropy is required http://nxtra.org/nxt-client/js/passphrasegenerator.js With all new browsers (Chrome, Firefox, IE 11) it uses crypto.getRandomValues which should be safe, but with IE 10 ...
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1answer
235 views

Danger of hidden html form uploading users local files without their knowledge

Is there a danger that a webpage could have a hidden form with a file upload input and js script that would try and take a random guesses at files on a users system and attach them to the form and ...
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4answers
100 views

What is the technique to determine if a user is “reading” a page called? (similar to “infinite scroll”)

When I read an article at Salon.com I notice that the "overflow content" (where I need to scroll down) is loaded on demand. I can't imagine this being a useful bandwidth savings technique, so the ...
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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 ...
3
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2answers
159 views

Security of Firefox extensions such as Mailvelope

I am asking these question because I am not very familiar with javascript or the Firefox plugin/extension system. The specific context is the Mailvelope pgp extension but the questions are general and ...
3
votes
1answer
371 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 ...
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4answers
737 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 ...
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2answers
113 views

User privileges for unsanatized code

We all know there are still vulnerable code out there even though they may or may not get exploited and found for hacking attempts. I've seen people do it countless times and have a possibly plausible ...
3
votes
1answer
269 views

Client-side cross-site access in SSL environment - when it's still possible to do?

I'm trying to imagine an secure sandboxed environment for an application which is big and unexplored, and may contain backdoors. It would live under chroot/virtual environment with no outgoing ...
3
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1answer
88 views

What's the advantage of passing credit cards via javascript vs. over the server (without saving it)?

I've noticed current credit card gateways like stripe and wepay encourage sending the credit card number via their js framework (which would use some iframe jsonp magic to pass the data). To my ...
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1answer
197 views

Predicting Math.random() numbers?

I was reading up on the documentation for Math.random() and I found the note: Math.random() does not provide cryptographically secure random numbers. Do not use them for anything related to ...
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3answers
95 views

Temporary XSS Vulnerability

I found xss on a textarea field. When you enter a character to this field it output the character in real time so when I input the following code: <input onclick=alert(document.cookie)> there ...
3
votes
1answer
176 views

How can I successfully perform an xss attack on a dummy website? [closed]

in my security course, we were told to practice an xss attack using firefox on this website; http://permalink.co/ No worries, this is a website specifically setup for us to practice ...
3
votes
3answers
150 views

What's the best way to secure the responses in a single page web app after logout?

I've read some of the great responses to storing and passing session keys in a single page web application (i.e., a web "site" that runs mostly on the client-side, getting data from the server by ...
3
votes
1answer
87 views

Is it any more secure to use a HTML form instead of a javascript popup?

Assuming both use session authentication, token validation and forced https: Is there any difference in security between submitting data via a JS popup <> ajax endpoint, and a standard web page ...
3
votes
1answer
938 views

Access-Control-Allow-Origin header spoofing?

Is it possible for a attacker to spoof the Access-Control-Allow-Origin header? Or, is it secure enough to protect resource access via the Access-Control-Allow-Origin header? I'm trying to make an ...
3
votes
1answer
385 views

How can I use certificates to secure my webservices? What is available to javascript?

I have a few web services that are accessed over public wifi connections and I think it would be a good idea to issue certificates to encrypt data, prevent MITM, and invalid impersonation (beyond what ...
3
votes
2answers
254 views

How to defend against invalid UTF7/8 that hides a <script> tag?

I'm scanning HTML before it reaches a browser, and I've just heard about a type of exploit that uses invalid UTF7 or UTF8 sequences to embed an otherwise invisible script tag, which is used to execute ...
3
votes
2answers
98 views

Limiting latter dom-based XSS when setting document.title

Given some JavaScript which modifies the page's title by taking in variable data document.title = someVariable I am looking to address dom based XSS while keeping the title fairly readable. ...
3
votes
1answer
106 views

Securely identify clients by web app

I have a web service S that provides certain services. There are two web apps, A1 and A2, both on different servers within the same VPN, which I trust and want to grant access to my web service. ...
3
votes
1answer
1k views

How to secure my REST implementation for an ember.js app

I've been searching and searching for what seems days and have not come up with any definitive answer on a solution to my problem. To explain without going into terrible detail I am building a store, ...
3
votes
0answers
69 views

Is the use of JavaScript for cryptography ever appropriate in the browser? [duplicate]

Possible Duplicate: How secure is aSSL (javascript)? Does it effectively mimic SSL? After some searching around, I realized we don't have an easily visible canonical question about this on ...
2
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5answers
2k views

Is converting `<` to `&lt;` sufficient to prevent execution of JavaScript from arbitrary HTML?

This is kind of a bar-bet question. An acquaintance of mine has made the claim that, given an arbitrary glob of HTML, it can be completely prevented from executing JavaScript if, before slapping it ...
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3answers
2k views

Javascript containing a long hexadecimal string and eval: is this suspicious?

At the bottom of the index.php file for a simple “contact us” form, I found the following (some whitespace and newlines added): try {if(window.document)--document.getElementById('12')} catch(qq) ...
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2answers
12k views

Best Approach for removing XSS Vulnerability

I have been developing a Webobjects application, and I found that my application is vulnerable to XSS through URL, but not when malicious input like <script>alert("hi")</script> is input ...
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2answers
59 views

Is is possible to create a “signature” for a piece of JavaScript

Bear with me, I may have asked this question in a botched way. So I need some JavaScript code that creates a signature of JavaScript that is stored in a string. Here is an example: presignature = ...
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4answers
2k views

Without using SSL, what's the most secure way to make an AJAX request to a PHP page?

It was suggested over at stackoverflow that I try my question here. This is it verbatim: So, it's impossible to do AJAX requests securely without using SSL. I get it. You can either view-source the ...