HTML (HyperText Markup Language) is a language used to create web pages using tags inline with the content to indicate to browsers how to display that content, using the tags to interpret formatting, images, scripts and other content.

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8
votes
1answer
2k views

What are the benefits and drawbacks of the HTML5 Keygen element?

As of January 2013, what are the potential benefits and drawbacks of the HTML5 Keygen element?
79
votes
5answers
38k views

Should websites be allowed to disable autocomplete on forms or fields?

Currently, there is an HTML form/input attribute called autocomplete, which, when set to off, disables autocomplete/autofill for that form or element. Some banks seem to use this to prevent password ...
1
vote
3answers
185 views

Can these html tags and attribs make my site vulnerable?

I am developing a social website and want to allow user ONLY these html tags and attributes in their posts: tags: <img>, <b>, <strong>, <blockquote>, <a> attributes: '...
6
votes
2answers
1k views

Escaping rich text editor output

When having a rich text editor on a web application, what is the best way to escape HTML entities and prevent XSS attacks but keep the formatting (<b>, <i>, <u>, ...etc.) ?
2
votes
2answers
2k views

If using htmlentities or htmlspecialchars functions is enough for block XSS attack

I know this question was discussed on net various times. and people give some example how to bypass these functions through passing some code. But here one issue, All example of htmlentities/...
6
votes
2answers
850 views

Workarounds for :visited CSS History reconnaissance

Several years ago it was possible to use a:visited { background: url('/log.php'); } to figure out on what website user has been previously. But now it is restricted by browsers. Is there any ...
5
votes
3answers
123 views

Input validation: how to do it if I must accept HTML as part of my input?

I'm writing a service which receives FHIR data and it stores it. FHIR is an HL7 healthcare information standard format which contains HTML by definition, embedded into a JSON or XML, (to ensure human-...
3
votes
5answers
2k views

Is it secure to use jQuery on the server-side for user input validation?

I'm thinking about using jQuery on the server-side (node.js) to validate user input (filter tags, remove every attributes except href, rel, target & style, modify css rules which are applied ...
9
votes
3answers
961 views

Any eventhandlers that apply to hidden elements?

I'm trying to XSS a search field and my attack vector is getting reflected like this: <input type="text" id="txtRpHiddenKeyword" style="display: none;" value="ATTACK VECTOR HERE" /> Only ...
7
votes
6answers
1k views

Cleartext password in HTML

Is there any problem with outputing a user's password to the HTML in an hidden field (see use case below before flaming xD)? The use case is a registration form with two steps. The user fills in the ...
6
votes
1answer
323 views

How do I securely embed an <img> tag using a user-given URL?

If I hypothetically wanted to allow users to use an avatar from an arbitrary URL like this: <img class="avatar" src="{user input}" /> There are many problems that I can think of: There are ...
2
votes
1answer
94 views

How to make the most secure text editor in Django?

As a follow up to this question, I'm wondering what is the most secure way (using either markup or markdown) to allow users to format their inputs and upload images in a Django app? I'm not asking ...
2
votes
1answer
877 views

HTML iframe security exploit

Can somebody explain if there's something malicious in this HTML, The width and height of the iframe ares set to 1 and it's out of the view with top: -100px; statement. I believe it takes some some ...