CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Scope: Confidentiality, Integrity, Availability

Impact: Read Application Data, Modify Application Data

Notes: This weakness is usually exploited by using a special attribute of objects called proto, constructor, or prototype. Such attributes give access to the object prototype. An attacker can inject attributes that are used in other components by adding or modifying attributes of an object prototype. This creates attributes that exist on every object, or replace critical attributes with malicious ones. This can be problematic if the product depends on existence or non-existence of certain attributes, or uses pre-defined attributes of the object prototype (such as hasOwnProperty, toString, or valueOf).

Scope: Availability

Impact: DoS: Crash, Exit, or Restart

Notes: An attacker can override existing attributes with ones that have incompatible type, which may lead to a crash.