CVE-2021-4356

Frontend File Manager <= 18.2 - Unauthenticated Arbitrary File Download

9.0 Critical

The Frontend File Manager plugin for WordPress is vulnerable to Unauthenticated Arbitrary File Download in versions up to, and including, 18.2. This is due to lacking authentication protections, capability checks, and sanitization, all on the wpfm_file_meta_update AJAX action. This makes it possible for unauthenticated attackers to download arbitrary files on the site, potentially leading to site takeover.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

1.52%Up 1.5 points since Jun 7, 2023

What each source reports

CVE List Score used 9.0

Frontend File Manager <= 18.2 - Unauthenticated Arbitrary File Download

Record: CVE-2021-4356
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness: CWE-862
Updated: 2026-11-02

EUVDEUVD-2021-34183 9.0

Record: EUVD-2021-34183
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-538r-g5r4-2c2w 9.0

The Frontend File Manager plugin for WordPress is vulnerable to Unauthenticated Arbitrary File...

Record: GHSA-538r-g5r4-2c2w
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness: CWE-862
Updated: 2026-11-02

NVD 9.0

Record: CVE-2021-4356
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-862
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-4356 is a critical vulnerability (CVSS 9.0) in Najeebmedia Frontend File Manager Plugin, published June 7, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.52%, the 74th percentile. No source names a fixed version.