msgpack5 is a msgpack v5 implementation for node.js and the browser. In msgpack5 before versions 3.6.1, 4.5.1, and 5.2.1 there is a "Prototype Poisoning" vulnerability. When msgpack5 decodes a map containing a key "__proto__", it assigns the decoded value to __proto__. Object.prototype.__proto__ is an accessor property for the receiver's prototype. If the value corresponding to the key __proto__ decodes to an object or null, msgpack5 sets the decoded object's prototype to that value. An
Часто на собеседовании опытный разработчик может спросить у начинающего: «Что такое __proto__ и prototype, и чем они отличаются?». Обычно этот вопрос либо ставит в тупик, либо на него отвечают заученной мантрой из видео «50 вопросов на собеседовании»: « __proto__ — это ссылка на prototype, а prototype —
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.
All versions of package dset are vulnerable to Prototype Pollution via 'dset/merge' mode, as the dset function checks for prototype pollution by validating if the top-level path contains __proto__, constructor or protorype. By crafting a malicious object, it is possible to bypass this check and achieve prototype pollution.