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Fencer Vulns
critical 9.0

CVE-2021-4356 json

Frontend File Manager <= 18.2 - Unauthenticated Arbitrary File Download

published 2023-06-07 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34183

cvss
9.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

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.

Patch / fix

  • nmedia Frontend File Manager Plugin 18.3

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
22 mo ago

Exploit prediction

1.52% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • blog.nintechnet.com https://blog.nintechnet.com/wordpress-frontend-file-manager-plugin-fixed-multiple-critical-vulnerabilities/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • nmedia Frontend File Manager Plugin

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.