NodeJS/hoek/1.0.1

hoek subject to prototype pollution via the clone function.

hoek versions prior to 8.5.1, and 9.x prior to 9.0.3 are vulnerable to prototype pollution in the clone function. If an object with the proto key is passed to clone() the key is converted to a prototype. This issue has been patched in version 9.0.3, and backported to 8.5.1.

Prototype Pollution in hoek

Versions of hoek prior to 4.2.1 and 5.0.3 are vulnerable to prototype pollution.

The merge function, and the applyToDefaults and applyToDefaultsWithShallow functions which leverage merge behind the scenes, are vulnerable to a prototype pollution attack when provided an unvalidated payload created from a JSON string containing the __proto__ property.

This can be demonstrated like so:

var Hoek = require('hoek');
var malicious_payload = '{"__proto__":{"oops":"It works !"}}';

var a = {};
console.log("Before : " + a.oops);
Hoek.merge({}, JSON.parse(malicious_payload));
console.log("After : " + a.oops);

This type of attack can be used to overwrite existing properties causing a potential denial of service.

Recommendation

Update to version 4.2.1, 5.0.3 or later.

hoek prototype pollution

hoek node module before 5.0.3 and before 4.2.1 suffers from a prototype pollution vulnerability via 'merge' and 'applyToDefaults' functions, which allows a malicious user to modify the prototype of 'Object' via proto, causing the addition or modification of an existing property that will exist on all objects.