How severe is CVE-2021-21020?

CVE-2021-21020 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-21020 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21020?

CVE-2021-21020 primarily affects Magento. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-21020?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-21020 published?

CVE-2021-21020 was published on 2021-02-11 and last updated on 2026-06-17.

CVE-2021-21020

CVE-2021-21020 is a medium-severity vulnerability in Magento with a CVSS 3.x base score of 5.3. 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-284.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.3
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Magento
Published: 2021-02-11
Last modified: 2026-06-17

Description

Magento versions 2.4.1 (and earlier), 2.4.0-p1 (and earlier) and 2.3.6 (and earlier) are vulnerable to an access control bypass vulnerability in the Login as Customer module. Successful exploitation could lead to unauthorized access to restricted resources.

Frequently asked questions

What is CVE-2021-21020?: Magento versions 2.4.1 (and earlier), 2.4.0-p1 (and earlier) and 2.3.6 (and earlier) are vulnerable to an access control bypass vulnerability in the Login as Customer module. Successful exploitation could lead to unauthorized access to restricted resources.
How severe is CVE-2021-21020?: CVE-2021-21020 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-21020 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21020?: CVE-2021-21020 primarily affects Magento. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-21020?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21020 published?: CVE-2021-21020 was published on 2021-02-11 and last updated on 2026-06-17.

References

https://helpx.adobe.com/security/products/magento/apsb21-08.html

Affected products (10)

cpe:2.3:a:magento:magento:*:*:*:*:commerce:*:*:*
cpe:2.3:a:magento:magento:*:*:*:*:open_source:*:*:*
cpe:2.3:a:magento:magento:2.3.6:-:*:*:commerce:*:*:*
cpe:2.3:a:magento:magento:2.3.6:-:*:*:open_source:*:*:*
cpe:2.3:a:magento:magento:2.4.0:-:*:*:commerce:*:*:*
cpe:2.3:a:magento:magento:2.4.0:-:*:*:open_source:*:*:*
cpe:2.3:a:magento:magento:2.4.0:p1:*:*:commerce:*:*:*
cpe:2.3:a:magento:magento:2.4.0:p1:*:*:open_source:*:*:*
cpe:2.3:a:magento:magento:2.4.1:-:*:*:commerce:*:*:*
cpe:2.3:a:magento:magento:2.4.1:-:*:*:open_source:*:*:*

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