No exploitation reportedFix available

CVE-2021-21016

Q: Is CVE-2021-21016 actively exploited?

Active exploitation of CVE-2021-21016 has not been confirmed. Its EPSS score was 4.9% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-21016?

CVE-2021-21016 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-02-11
Fixed in2.3.6
WeaknessCWE-78

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Magento versions 2.4.1 (and earlier), 2.4.0-p1 (and earlier) and 2.3.6 (and earlier) are vulnerable to OS command injection via the WebAPI. Successful exploitation could lead to remote code execution by an authenticated attacker. Access to the admin console is required for successful exploitation.

Timeline

dates in UTC

2021-02-1120:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-21016?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-21016?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Magento

Branch	Affected	Fixed in	Source
2.3	< 2.3.6	2.3.6	NVD
2.3	= 2.3.6	no fix published	NVD
2.4	= 2.4.0	no fix published	NVD
2.4	= 2.4.1	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Magento to 2.3.6

Advisories and patches

helpx.adobe.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.09.1read 2026-10-23
NVDCVSS 2.09read 2026-10-23
CNAweakness (CWE)CWE-78read 2026-10-23
NVDweakness (CWE)CWE-78read 2026-10-23
FIRST EPSSEPSS score4.9 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Published: 2021-02-11
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-21016?

Is CVE-2021-21016 actively exploited?

Active exploitation of CVE-2021-21016 has not been confirmed. Its EPSS score was 4.9% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-21016?

CVE-2021-21016 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

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