CVE Vulnerabilities


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

Published: Nov 01, 2023 | Modified: Nov 09, 2023
CVSS 3.x
CVSS 2.x

Prototype pollution in bitrix/templates/bitrix24/components/bitrix/menu/left_vertical/script.js in Bitrix24 22.0.300 allows remote attackers to execute arbitrary JavaScript code in the victim’s browser, and possibly execute arbitrary PHP code on the server if the victim has administrator privilege, via polluting __proto__[tag] and __proto__[text].


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
Bitrix24 Bitrix24 22.0.300 (including) 22.0.300 (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