CVE-2021-21413

What it is

isolated-vm is a library for nodejs which gives you access to v8's Isolate interface. Versions of isolated-vm before v4.0.0 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. This is addressed in v4.0.0 through a series of related changes.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. High risk of data exposure, data tampering.

Exploit odds

0.7% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-03-30 23:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:35 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.7% in the next 30 days (EPSS).
• Severity: 8.0 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-03-30 23:15 UTC

Last modified

2026-06-17 03:35 UTC

Exploit probability

0.7% · EPSS, next 30 days

Weakness

CWE-913

Record status

Modified

Affected

• isolated-vm Project isolated-vm < 4.0.0

Attack profile CVSS 3.1 · 8.0

Attack vector

Adjacent network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-21413.md and follow it. Check whether this project is affected by CVE-2021-21413. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge