Cross-Site Scripting: An attack method that involves injection of code or markup into a webpage. There are three major types of XSS: Reflected XSS, Stored XSS (aka persistent XSS), DOM-based XSS (aka client side XSS).

learn more… | top users | synonyms

1
vote
2answers
284 views

I need explanation on how serious these vulnerabilities are?

I have found two vulnerabilities on my college site and I want to report them but don't know if these are "really" vulnerabilities : RFI inside SWF file. Example: ...
3
votes
5answers
1k views

referrer checking as a defence for XSS attack

After reading the question about referrer and the answer of @D.W., I did not understand the following part: XSS defense. Strict referer checking can make reflective XSS attacks harder, because ...
3
votes
4answers
1k views

What XSS attacks doesn't “Reflective XSS Protection” defeat?

Its been quite a while since I have played with cross site scripting vulnerabilities but today I came across a website today that was crying out to be tested for a basic XSS vulnerability. So ...
7
votes
2answers
788 views

Drupal filters XSS with regexes. What could bypass it?

Drupal filters HTML strings against XSS attacks using regexes: http://api.drupal.org/api/drupal/includes%21common.inc/function/filter_xss/7 However, as a lot of people know, HTML can't be parsed with ...
0
votes
1answer
1k views

How to escape user input in a value of javascript object?

How to properly escape user-controlled input when it's inserted as a value in JSON object? <script> $(document).ready(function() { new MyObject({ key1: "user_input", key2: ...
0
votes
1answer
570 views

How to show xss alert box when you are inside function in <script> tag?

For example we have this: <script type="text/javascript" charset="utf-8"> $(function () { var stranica = "#aXSSinjection point"; var stranicaContainers = $('div.stabs > ...
4
votes
2answers
208 views

filtering content in Content disposition header

I was reading "The Tangled Web"(A book that I'm enjoying very much) and I have a doubt in the following excerpt taken from it :- When Handling User-Controlled Filenames in Content-Disposition Headers ...
4
votes
2answers
525 views

CSRF Protection on static pages

I have a static site which has forms. The forms submit to a Rails endpoint which captures the submitted data. The static site and the Rails endpoint are on the same domain, on different subdomains and ...
8
votes
3answers
339 views

E-mail read receipt through XSS

I recently stumbled upon a really silly/unsafe but an interesting way to get a read receipt of an e-mail. I'm not 100% sure if the method in use works, which is why I'm asking it here. G-mail does ...
2
votes
5answers
4k views

Efficient way for finding XSS vulnerabilities?

Manual (reliable) way: Put string containing characters that have special meaning in HTML into some parameter of HTTP request, look for this string in HTTP response (and possibly) in other places ...
5
votes
2answers
3k views

How can I prevent reflected XSS in my JSON web services?

I have a web service that takes POST data (JSON) and returns part of the request object in the JSON response. This is open to XSS if the response is rendered as HTML by the browser since someone ...
6
votes
5answers
4k views

XSS : Blacklist characters vs. whitelist

I have been studying to prevent my web app against XSS. I read about it on OWASP and other security channels, they all say that use ESAPI and similar library, and also do input filtering through ...
2
votes
2answers
728 views

Is Drupal's filter_xss enough for filtering HTML?

Drupal has filter_xss function. Is it safe to use for filtering arbitrary user HTML input? If not, what should be used instead when using Drupal 7? This questuion is a duplicate of Drupal's built-in ...
4
votes
1answer
1k views

XSS inside CSS when " is encoded?

I'm trying to make XSS work on one site.It allows me to edit CSS which is then included inside web page source , but it won't allow me to use " , only ' . Source is like this: body { margin: 0; ...
5
votes
1answer
221 views

Where does the responsibility lie for a XSS vulnerability

I am an avid user of Workflowy (online outliner/note taking tool) and I installed the Chrome extension 'Workflowy for Coders', which formats the text within notes. I discovered that one of my notes ...
2
votes
4answers
3k views

Current best practices to prevent persistent XSS attacks

I have a text field that allows the user to type whatever he/she wants. After saving, the results are later displayed on the screen to potentially many people. XSS seems a bit like black magic to ...
3
votes
4answers
4k views

What is the danger of Reflected Cross Site Scripting?

What is the danger of Reflected Cross Site Scripting? I understand the Reflected XSS is dangerous, because it's possible. But what practical attacks can be performed using Reflected XSS?
0
votes
1answer
595 views

scanning my site for JavaScript/XSS vulnerabilities [closed]

It have had a report that my site may have a security issue and there is some JavaScript loading 10 times per second. www.ayrshireminis.com Is there anyway that I can "scan" my site to check if ...
1
vote
2answers
175 views

Why ban XSS instead of flagging it?

Consider a browser that allows an XMLHttpRequest downloaded from foo.net to make requests to bar.net, but attaches a XHR-Origin: http://foo.net (or possibly a more descriptive value like ...
1
vote
1answer
206 views

Web Application Firewall Rule Optimization

Following are the two Rules taken from ModSecurity CRS core Ruleset. These two rules are base Rules for XSS attacks. If we look at these two rules their variables and actions are same what they differ ...
3
votes
2answers
345 views

What is cross-site-scripting? [duplicate]

Possible Duplicate: Can anybody explain XSS to an idiot? First I ask is there an aboslute definition? I've done some Googleing and it seems like everyone says something different. On SO ...
4
votes
2answers
303 views

Can anybody recommend any gems for checking security vulnerabilities?

I want to check one of my RoR projects for security vulnerabilities. So can anybody recommend any gems for my needs?
1
vote
2answers
1k views

HTTP TRACE vulnerability discovered - what should I do

First, why is HTTP TRACE method allowed on a website Isn't it a bad thing for web server or its users' security? Second, when I run the following PHP script via my browser... <?php $service_port ...
3
votes
2answers
521 views

Risks of serving untrusted content under HTTP Content-Type: text/plain?

Am I gonna run into XSS attacks by doing this, or will a file download be prompted? Are there security problems that would rise in a modern browser?
4
votes
2answers
412 views

Are sandboxes overrated?

I've stumbled upon the following on the blog of the NoScript developer Giorgio Maone. First, he quotes the following ArsTechnica article about an XSS bug in Adobe Flash: As useful as sandboxes ...
7
votes
1answer
6k views

Does Google Chrome protect against cross site scripting (XSS)?

In Firefox I've been using the NoScript extension to protect myself from certain kinds of malware attacks. NoScript is well known as a very powerful extension for Firefox and introduced protection ...
3
votes
3answers
2k views

Why doesn't the same origin policy block get requests what contain arguments?

From what I understand, the same origin policy prevents scripts in a web page from talking to servers outside of the present domain (using post, xmlhttprequest, etc). I assumed that get requests ...
3
votes
2answers
829 views

Is it possible to forge post request and bypass maxlength in input box?

I have input box with maxlength=12, and that input box is vulnerable to xss. But because of maxlength 12 it is not possible to construct any really valid xss vector. The user input is stored in the ...
3
votes
5answers
452 views

Does setting the cookie-path protect me from XSS from another context?

Lets say I am using a reverse proxy with URL rewriting that provides access to 2 different applications http://www.example.com/app1/ and http://www.example.com/app2/. I don't want those ...
1
vote
1answer
609 views

LFI or RFI from XSS?

Could XSS lead us to the Local File Include or Remote File Include? I read article that it's possible to upload shell via XSS vulnerability, but I still have no idea how it had been achieved.
3
votes
1answer
251 views

Multibyte Character Exploits JSP/PostgreSQL

I am trying to secure a web application, written in Java/JSP and running on PostgreSQL, against SQL injection. I ran into this very interesting answer, which refers to PHP and MySQL. Is there any ...
2
votes
3answers
320 views

sanitizing likes/unlikes in application?

I've got a function in my app where users can click on a "thumbs up" image and a like is recorded in the database; all that's recorded is the user's ID and the ID of the post that the user liked. I ...
0
votes
2answers
147 views

Where is cross-site scripting code processed?

Where does the snippet or Javascript get processed when we enter that in input box of HTML page or any URL? Does it go to the server and come back or does the browser process it?
5
votes
3answers
653 views

Is it a security risk to embed a commenting service (like Disqus) into our site?

Can commenting services like Disqus, IntenseDebate, etc. pose a security risk for corporations? Edit: What risks could arise when embedding such services into corporate websites?
7
votes
3answers
4k 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. ...
2
votes
3answers
3k views

How to fix specific XSS issues in URL via php?

I am using Netsparker community edition for checking my app for any general security holes. I'm getting a lot of following XSS probable issue areas: my_php_file.php?nsextt=" ...
1
vote
2answers
2k views

header injection + codeigniter

I'm reading through Mozilla's Secure Coding Guidelines, and found this statement: Don't trust any user data (input, headers, cookies etc). Validate it before using it I'm using the codeigniter ...
2
votes
1answer
1k 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
5answers
3k views

How can I execute a XSS with these conditions?

I am trying to learn penetration testing and I have downloaded a vulnerable application called "Bodgeit Store". I have finished almost all the challenges except one which is to execute a Cross-Site ...
21
votes
2answers
3k 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 ...
-1
votes
2answers
174 views

Is it Illegal to break out of a forum post by using CSS for example?

Is it illegal in the UK to post styling that breaks out of a post? For instance, if styling were allowed here and I were to use it to change some stackexchange pictures on this page, would that be ...
2
votes
2answers
7k 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 ...
3
votes
3answers
2k views

XSS : Content-type: application/json

Background information - Application responds to request to a particular URL with content-type: application/json JSON response contains a parameter from the request Escapes the quote with a slash ...
5
votes
4answers
11k views

Security issues using iframes

We are looking to move to iframes due to technical challenges. By moving to iframes it will be easier to manage the technical issues. But we are not totally sure of security implications of iframes. ...
6
votes
2answers
1k views

Is e-mail a direct vector for XSS

I'm curious if there is a way to execute XSS via email. I am not talking about using e-mail as a way to deliver a link that has reflected XSS in it. I'm talking about sending an email from ...
11
votes
2answers
931 views

Interpolique: transparently preventing SQL Injection and XSS with base64 encoding, what happened?

For the keynote at The Next HOPE a couple of years ago, Dan Kaminsky unveiled Interpolique (the talk is really fun btw). The problem he raised was how to defend against injection attacks, including ...
2
votes
2answers
157 views

For untrusted user upload sites: what should the contents of crossdomain.xml and clientaccesspolicy.xml be?

Flash has a long history of ignoring MIME types of files and reading the file directly for executable content or for cross domain execution permissions. That means a malicious user can take advantage ...
1
vote
1answer
3k views

Will JavaScript be executed which is in an HREF?

I located an issue with a site where I can insert a script tag into the href of an anchor tag: <a href="<script>alert(8007)</script>">Click Me</a> What I am trying to ...
3
votes
1answer
396 views

Notable XSS attacks in 2011

I am wondering what notable events in XSS attacks we saw in 2011. What big events hit the infosec community in regards of XSS? I am thinking of specific events like for example the Samy worm in 2007 ...
2
votes
2answers
1k views

How do I figure out how malware infected my server, and the subsequent sites on the server?

I recently was in charge of fixing our server at work, and cleaning the sites on it. We were infected with some malware that injected some code into some of our clients websites. Apparently, there was ...