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.
- Likelihood of attack
- Not rated by MITRE
- Typical severity
- Medium
- Abstraction
- StandardA specific methodology or technique used in an attack.
Mechanism of attack: Abuse Existing Functionality
Prerequisites
- The victim's browser is not configured to reject all cookiesThe victim visits a website that serves the attackers' evercookie
Mitigations
- Design: Browser's design needs to be changed to limit where cookies can be stored on the client side and provide an option to clear these cookies in all places, as well as another option to stop these cookies from being written in the first place.
- Design: Safari browser's private browsing mode is currently effective against evercookies.
Related weaknesses (CWE)
ATT&CK techniques (CAPEC taxonomy mapping)
Across MITRE's defensive frameworks
Linked through the 1 ATT&CK technique above.
Counter with D3FEND
Defensive techniques MITRE D3FEND maps to the same ATT&CK techniques.
- D3-ANCIAuthentication Cache Invalidation1 shared
- D3-CCSACredential Compromise Scope Analysis1 shared
- D3-CHCredential Hardening1 shared
- D3-CRCredential Revocation1 shared
- D3-CROCredential Rotation1 shared
- D3-CTSCredential Transmission Scoping1 shared
- D3-DUCDecoy User Credential1 shared
- D3-MFAMulti-factor Authentication1 shared
- D3-RICReissue Credential1 shared
Detect with CAR
MITRE CAR analytics that cover the same ATT&CK techniques.