CVE Vulnerabilities


Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Published: May 01, 2022 | Modified: May 11, 2022
CVSS 3.x
CVSS 2.x
7.5 HIGH

The package dexie before 3.2.2, from 4.0.0-alpha.1 and before 4.0.0-alpha.3 are vulnerable to Prototype Pollution in the Dexie.setByKeyPath(obj, keyPath, value) function which does not properly check the keys being set (like proto or constructor). This can allow an attacker to add/modify properties of the Object.prototype leading to prototype pollution vulnerability. Note: This vulnerability can occur in multiple ways, for example when modifying a collection with untrusted user input.


The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

Affected Software

Name Vendor Start Version End Version
Dexie Dexie * 3.2.2 (excluding)
Dexie Dexie 4.0.0-alpha1 (including) 4.0.0-alpha1 (including)
Dexie Dexie 4.0.0-alpha2 (including) 4.0.0-alpha2 (including)

Extended Description

By adding or modifying attributes of an object prototype, it is possible to create 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 object prototype (such as hasOwnProperty, toString or valueOf). 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. This weakness is often found in code that assigns object attributes based on user input, or merges or clones objects recursively.

Potential Mitigations