CVE-2021-33420: A deserialization issue discovered in inikulin replicator before 1.0.4 allows remote attackers to run arbitrar

Q: How do I fix CVE-2021-33420?

replicator: upgrade to 1.0.4. Exact commands for each OS are on this page.

Q: Is CVE-2021-33420 being exploited?

CVE-2021-33420 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-33420 affect?

CVE-2021-33420 affects replicator. Severity is critical (CVSS 9.8). 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.

Q: How urgent is CVE-2021-33420?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2021-33420 is a critical-severity flaw (CVSS 9.8) affecting replicator. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-502
Published	2022-12-15
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: replicator project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-12-15 19:15 UTCPublished CVE record published
2026-06-17 03:54 UTCUpdated Record last modified

replicator project replicator UPGRADE

Affected: < 1.0.4

Fixed in: 1.0.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy replicator || rpm -q replicator || replicator --version

2. UPGRADE to 1.0.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade replicator

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade replicator

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-33420?

replicator: upgrade to 1.0.4. Exact commands for each OS are on this page.

Is CVE-2021-33420 being exploited?

CVE-2021-33420 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-33420 affect?

CVE-2021-33420 affects replicator. Severity is critical (CVSS 9.8). 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.

How urgent is CVE-2021-33420?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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