CVE-2021-36021 | Magento Commerce CMS Page Improper Input Validation Could Lead To Remote Code Execution

Magento versions 2.4.2 (and earlier), 2.4.2-p1 (and earlier) and 2.3.7 (and earlier) are affected by an Improper input validation vulnerability within the CMS page scheduled update feature. An authenticated attacker with administrative privilege could leverage this vulnerability to achieve remote code execution on the system.

Published: 2023-09-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36021 is rated Moderate Risk (56.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.95%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-36021

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.31% 1.95% +0.64%
2 2026-06-01 0.98% 1.31% +0.32%
3 2026-03-17 — 0.98% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36021

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 5.9 [email protected]
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 5.9 [email protected]

Weakness enumeration for CVE-2021-36021

GitHub Security Advisory for CVE-2021-36021

GHSA-4g27-q2w9-m8m8 · Severity: critical · Ecosystem: composer — Magento affected by remote code execution vulnerability in the CMS page scheduled update feature

Affected software / configurations for CVE-2021-36021

Vendor Product Version Raw CPE
magento magento < 2.3.7 cpe:2.3:a:magento:magento:*:*:*:*:commerce:*:*:*
magento magento < 2.3.7 cpe:2.3:a:magento:magento:*:*:*:*:open_source:*:*:*
magento magento >= 2.4.0, < 2.4.2 cpe:2.3:a:magento:magento:*:*:*:*:commerce:*:*:*
magento magento >= 2.4.0, < 2.4.2 cpe:2.3:a:magento:magento:*:*:*:*:open_source:*:*:*
magento magento 2.3.7 cpe:2.3:a:magento:magento:2.3.7:-:*:*:commerce:*:*:*
magento magento 2.3.7 cpe:2.3:a:magento:magento:2.3.7:-:*:*:open_source:*:*:*
magento magento 2.4.2 cpe:2.3:a:magento:magento:2.4.2:-:*:*:commerce:*:*:*
magento magento 2.4.2 cpe:2.3:a:magento:magento:2.4.2:-:*:*:open_source:*:*:*
magento magento 2.4.2 cpe:2.3:a:magento:magento:2.4.2:p1:*:*:commerce:*:*:*
magento magento 2.4.2 cpe:2.3:a:magento:magento:2.4.2:p1:*:*:open_source:*:*:*

References for CVE-2021-36021

cvelogic Threat Intelligence