Is CVE-2021-33420 in the CISA KEV catalog?

No. CVE-2021-33420 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-33420?

CVE-2021-33420 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2021-33420?

CVE-2021-33420 has an EPSS score of 1.61% (73th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-33420?

Upgrade replicator to 1.0.4 or later.

CVE & CISA-KEV Catalog

CVE-2021-33420

CRITICALEPSS 73th pctl

9.8

CVSS v3

NVD

Description

A deserialization issue discovered in inikulin replicator before 1.0.4 allows remote attackers to run arbitrary code via the fromSerializable function in TypedArray object.

CWE-502Deserialization of Untrusted Data

How to fix

Remediation Available

replicatorNVD

Affected:< 1.0.4Fixed in:1.0.4CVE-2021-33420derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

1.61%probability of exploitation in 30 days

73rdpercentile

Elevated risk: more likely to be exploited than 73% of all known CVEs.

References

Patch1

github.com

Exploit1

advisory.checkmarx.net

Third-Party Advisory2

Related Vulnerabilities

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-0669	High	7.2	100%	KEV + Ransom	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-35464	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2023-29300	Critical	9.8	100%	KEV + Ransom	-
CVE-2025-53770	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2022-47986	Critical	9.8	100%	KEV + Ransom	-

Embed a live status badge for CVE-2021-33420

Markdown

[![CVE-2021-33420](https://tridentstack.com/cve/badge/CVE-2021-33420.svg)](https://tridentstack.com/cve/CVE-2021-33420)

HTML

<a href="https://tridentstack.com/cve/CVE-2021-33420"><img src="https://tridentstack.com/cve/badge/CVE-2021-33420.svg" alt="CVE-2021-33420"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-04-21.