Cyber Resilience

CVE-2021-33420

CriticalPublic PoCRCE

Published: 15 December 2022

Published
15 December 2022
Modified
21 April 2025
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0186 83.5th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33420 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Replicator Project Replicator. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 16.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

replicator project
replicator
≤ 1.0.4

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-502

Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.

addresses: CWE-502

Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.

addresses: CWE-502

Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.

addresses: CWE-502

Validates or rejects untrusted serialized data before deserialization occurs.

addresses: CWE-502

Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.

addresses: CWE-502

Integrity verification of serialized information can detect tampering before deserialization occurs.

addresses: CWE-502

Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.

References