How severe is CVE-2021-43421?

CVE-2021-43421 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43421 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 43% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43421?

CVE-2021-43421 affects Std42 Elfinder. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43421?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-43421 published?

CVE-2021-43421 was published on 2022-04-07 and last updated on 2026-06-17.

CVE-2021-43421

CVE-2021-43421 is a critical-severity vulnerability in Std42 Elfinder with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 43% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-434.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 43% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Std42 Elfinder
Published: 2022-04-07
Last modified: 2026-06-17

Description

A File Upload vulnerability exists in Studio-42 elFinder 2.0.4 to 2.1.59 via connector.minimal.php, which allows a remote malicious user to upload arbitrary files and execute PHP code.

Frequently asked questions

What is CVE-2021-43421?: A File Upload vulnerability exists in Studio-42 elFinder 2.0.4 to 2.1.59 via connector.minimal.php, which allows a remote malicious user to upload arbitrary files and execute PHP code.
How severe is CVE-2021-43421?: CVE-2021-43421 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43421 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 43% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43421?: CVE-2021-43421 affects Std42 Elfinder. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43421?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-43421 published?: CVE-2021-43421 was published on 2022-04-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:std42:elfinder:*:*:*:*:*:*:*:*

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Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

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CVE-2026-40772 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions.
CVE-2026-40412 — Critical (CVSS 10.0): Unrestricted upload of file with dangerous type in Azure Orbital Spatio allows an unauthorized attacker to execute code…

Browse all CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities →