How severe is CVE-2021-24223?

CVE-2021-24223 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-2021-24223 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-24223?

CVE-2021-24223 affects N5 Upload Form Project N5 Upload Form. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-24223?

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-2021-24223 published?

CVE-2021-24223 was published on 2021-04-12 and last updated on 2026-06-17.

CVE-2021-24223

CVE-2021-24223 is a critical-severity vulnerability in N5 Upload Form Project N5 Upload Form with a CVSS 3.x base score of 9.8. 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-434.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: N5 Upload Form Project N5 Upload Form
Published: 2021-04-12
Last modified: 2026-06-17

Description

The N5 Upload Form WordPress plugin through 1.0 suffers from an arbitrary file upload issue in page where a Form from the plugin is embed, as any file can be uploaded. The uploaded filename might be hard to guess as it's generated with md5(uniqid(rand())), however, in the case of misconfigured servers with Directory listing enabled, accessing it is trivial.

Frequently asked questions

What is CVE-2021-24223?: The N5 Upload Form WordPress plugin through 1.0 suffers from an arbitrary file upload issue in page where a Form from the plugin is embed, as any file can be uploaded. The uploaded filename might be hard to guess as it's generated with md5(uniqid(rand())), however, in the case of misconfigured servers with Directory listing enabled, accessing it is trivial.
How severe is CVE-2021-24223?: CVE-2021-24223 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-2021-24223 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24223?: CVE-2021-24223 affects N5 Upload Form Project N5 Upload Form. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-24223?: 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-2021-24223 published?: CVE-2021-24223 was published on 2021-04-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:n5_upload_form_project:n5_upload_form:*:*:*:*:*:wordpress:*:*

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

CVE-2026-48283 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-48276 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Unrestricted Upload of File with Dangerous Type…
CVE-2026-57700 — Critical (CVSS 10.0): Unrestricted Upload of File with Dangerous Type vulnerability in Daan.Dev OMGF Pro allows Using Malicious Files. This…
CVE-2025-69129 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in WordPress & WooCommerce Scraper Plugin, Import Data from Any Site <= 1.0.7…
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 →