Search results
Results From The WOW.Com Content Network
Similarly to the cookie-to-header approach, but without involving JavaScript, a site can set a CSRF token as a cookie, and also insert it as a hidden field in each HTML form. When the form is submitted, the site can check that the cookie token matches the form token.
Simply printing (echoing) user input to the browser without checking it first is something that should be avoided in secure forms processors: if a user entered the JavaScript code < script > alert (1)</ script > into the firstname field, the browser would execute the script on the form_handler.php page, just as if it had been coded by the ...
Stopping an XSS attack when accepting HTML input from users is much more complex in this situation. Untrusted HTML input must be run through an HTML sanitization engine to ensure that it does not contain XSS code. Many validations rely on parsing out (blacklisting) specific "at risk" HTML tags such as the iframe tag, link and the script tag.
In data sanitization, HTML sanitization is the process of examining an HTML document and producing a new HTML document that preserves only whatever tags and attributes are designated "safe" and desired. HTML sanitization can be used to protect against attacks such as cross-site scripting (XSS) by sanitizing any HTML code submitted by a user.
The Ajax.Request below finds the current values of two HTML form input elements, issues an HTTP POST request to the server with those element name/value pairs, and runs a custom function (called showResponse below) when the HTTP response is received from the server:
Code injection is a computer security exploit where a program fails to correctly process external data, such as user input, causing it to interpret the data as executable commands. An attacker using this method "injects" code into the program while it is running.
Form, link and image elements could be referenced with a hierarchical name that began with the root document object. A hierarchical name could make use of either the names or the sequential index of the traversed elements. For example, a form input element could be accessed as either document.myForm.myInput or document.forms[0].elements[0].
An early use of CGI scripts was to process forms. In the beginning of HTML, HTML forms typically had an "action" attribute and a button designated as the "submit" button. When the submit button is pushed the URI specified in the "action" attribute would be sent to the server with the data from the form sent as a query string.