CVE-2021-21413

CVE-2021-21413 is a high-severity vulnerability in Isolated-vm Project Isolated-vm with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-913.

Key facts

Description

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.

Frequently asked questions

What is CVE-2021-21413?
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.
How severe is CVE-2021-21413?
CVE-2021-21413 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-21413 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21413?
CVE-2021-21413 affects Isolated-vm Project Isolated-vm. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21413?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21413 published?
CVE-2021-21413 was published on 2021-03-30 and last updated on 2026-06-17.

References

Affected products (1)

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