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HIGH7.8

GHSA-qxc2-j82w-r537

Faker: helpers.fake exploitable into arbritary code execution

Quick fix

GHSA-qxc2-j82w-r537 — @faker-js/faker: upgrade to the fixed version with the command below.

npm install @faker-js/faker@10.5.0

Details

### Summary

`faker.helpers.fake` can be tricked into arbritary code execution.

### Details

fakeEval.resolveProperty resolves properties on functions itself instead of resolving the nested function first. This can be addressed by recursively calling resolveProperty instead of accessing the property after one iteration.

### PoC

Go to https://fakerjs.dev/ Open Browser console and run

````ts await enableFaker(); // or import faker faker.rawDefinitions.test = (() => () => {}); // Any function that returns a function faker.helpers.fake(`{{test.constructor(alert('PowerLevel: Eval'))}}`); ````

### Impact

The Fake method claims:

> It is also NOT possible to use any non-faker methods or plain javascript in such patterns.

Which is objectively false, since any global gets fully accessible in the fake string.

Are you affected?

Enter the version of the package you're using.

Affected packages

npm/@faker-js/faker
Introduced in: 0Fixed in: 10.5.0
Fixnpm install @faker-js/faker@10.5.0

References