tarteaucitron.js is a compliant and accessible cookie banner. A vulnerability was identified in tarteaucitron.js prior to 1.20.1, where the addOrUpdate function, used for applying custom texts, did not properly validate input. This allowed an attacker with direct access to the sites source code or a CMS plugin to manipulate JavaScript object prototypes, leading to potential security risks such as data corruption or unintended code execution. An attacker with high privileges could exploit this vulnerability to modify object prototypes, affecting core JavaScript behavior, cause application crashes or unexpected behavior, or potentially introduce further security vulnerabilities depending on the applications architecture. This vulnerability is fixed in 1.20.1.
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.
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.