CAPEC-588: DOM-Based XSS

Description
This type of attack is a form of Cross-Site Scripting (XSS) where a malicious script is inserted into the client-side HTML being parsed by a web browser. Content served by a vulnerable web application includes script code used to manipulate the Document Object Model (DOM). This script code either does not properly validate input, or does not perform proper output encoding, thus creating an opportunity for an adversary to inject a malicious script launch a XSS attack. A key distinction between other XSS attacks and DOM-based attacks is that in other XSS attacks, the malicious script runs when the vulnerable web page is initially loaded, while a DOM-based attack executes sometime after the page loads. Another distinction of DOM-based attacks is that in some cases, the malicious script is never sent to the vulnerable web server at all. An attack like this is guaranteed to bypass any server-side filtering attempts to protect users.
Extended Description

Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.

Severity :

Very High

Possibility :

High

Type :

Detailed
Prerequisites

This table shows the other attack patterns and high level categories that are related to this attack pattern.

  • An application that leverages a client-side web browser with scripting enabled.
  • An application that manipulates the DOM via client-side scripting.
  • An application that failS to adequately sanitize or encode untrusted input.
Skills required

This table shows the other attack patterns and high level categories that are related to this attack pattern.

  • Medium Requires the ability to write scripts of some complexity and to inject it through user controlled fields in the system.
Taxonomy mappings

Mappings to ATT&CK, OWASP and other frameworks.

Resources required

None: No specialized resources are required to execute this type of attack.

Related CWE

A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful.

Visit http://capec.mitre.org/ for more details.