QID 982822

Versions of `isolated-vm` before v4.0.0, and especially before v3.0.0, have API pitfalls which may make it easy for implementers to expose supposed secure isolates to the permissions of the main nodejs isolate.

`Reference` objects allow access to the underlying reference's full prototype chain. In an environment where the implementer has exposed a `Reference` instance to an attacker they would be able to use it to acquire a `Reference` to the nodejs context's `Function` object.

Similar application-specific attacks could be possible by modifying the local prototype of other API objects.

Access to `NativeModule` objects could allow an attacker to load and run native code from anywhere on the filesystem. If combined with, for example, a file upload API this would allow for arbitrary code execution.

To address these issues the following changes were made in v4.0.0:
- Documentation was updated with more explicit guidelines on building secure applications.
- `Reference` instances will no longer follow prototype chains by default, nor will they invoke accessors or proxies.
- All `isolated-vm` API prototypes are now immutable.
- `NativeModule` constructor may only be invoked from a nodejs isolate.

Successful exploitation of this vulnerability may affect the confidentiality, integrity, and availability of the targeted user.