CAPEC-464: Evercookie

Description
An attacker creates a very persistent cookie that stays present even after the user thinks it has been removed. The cookie is stored on the victim's machine in over ten places. When the victim clears the cookie cache via traditional means inside the browser, that operation removes the cookie from certain places but not others. The malicious code then replicates the cookie from all of the places where it was not deleted to all of the possible storage locations once again. So the victim again has the cookie in all of the original storage locations. In other words, failure to delete the cookie in even one location will result in the cookie's resurrection everywhere. The evercookie will also persist across different browsers because certain stores (e.g., Local Shared Objects) are shared between different browsers.
Extended Description

The places a persistent cookie is stored on a victim's machine include: Standard HTTP Cookies, Local Shared Objects (Flash Cookies), Silverlight Isolated Storage, Storing cookies in RGB values of auto-generated, force-cached, PNGs using HTML5 Canvas tag to read pixels (cookies) back out, Storing cookies in Web History, Storing cookies in HTTP ETags, Storing cookies in Web cache, window.name caching, Internet Explorer userData storage, HTML5 Session Storage, HTML5 Local Storage, HTML5 Global Storage, HTML5 Database Storage via SQLite, among others.

Severity :

Medium

Possibility :

Type :

Standard
Relationships with other CAPECs

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

Prerequisites

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

  • The victim's browser is not configured to reject all cookiesThe victim visits a website that serves the attackers' evercookie
Skills required

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

Taxonomy mappings

Mappings to ATT&CK, OWASP and other frameworks.

Resources required

Evercookie source code

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.

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