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Fencer Vulns
critical 9.8

CVE-2021-24223 json

N5 Upload Form <= 1.0 - Unauthenticated Arbitrary File Upload to RCE

published 2021-04-12 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11137

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

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.

Exploit prediction

2.21% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/d7a72183-0cd1-45de-b98b-2e295b27e5db referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/jinhuang1102/CVE-ID-Reports/blob/12863f80ced5361e2e2c3f7209566ab3730aa37b/N5_upload.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Unknown N5 Upload Form

Classification

Weakness
  • CWE-434 Unrestricted Upload of File with Dangerous Type
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.