CVE-2021-47940

Critical
9.8
0.05.010.0
Year
2026
Published
May 10, 2026
Known Affected Devices
0
CVSS Score
9.8

What is CVE-2021-47940?

WordPress Plugin Download From Files version 1.48 and earlier contains an arbitrary file upload vulnerability that allows unauthenticated attackers to upload malicious files by exploiting the AJAX fileupload action. Attackers can send POST requests to the admin-ajax.php endpoint with the download_from_files_617_fileupload action, manipulating the allowExt parameter to bypass file type restrictions and upload executable files like PHP shells to the web root.

CVSS Vector Breakdown

CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV
Attack Vector
Network

Exploitable remotely over the network without requiring access to the local system.

AC
Attack Complexity
Low

No special conditions required. Exploit can be performed reliably and repeatedly.

PR
Privileges Required
None

No authentication required. Any anonymous user can exploit this vulnerability.

UI
User Interaction
None

No user interaction required. Exploit runs without any victim action.

S
Scope
Unchanged

Exploiting the vulnerability only affects the vulnerable component itself.

C
Confidentiality Impact
High

Complete loss of confidentiality. All data on the component may be exposed.

I
Integrity Impact
High

Complete loss of integrity. Attacker can modify any file or data on the component.

A
Availability Impact
High

Complete denial of service. The component becomes fully unavailable.

FAQ

How severe is CVE-2021-47940?

CVE-2021-47940 has a CVSS score of 9.8/10, rated as Critical. This is the highest severity level - immediate patching is strongly recommended.

What does the CVSS score mean for CVE-2021-47940?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2021-47940 scores 9.8/10 (Critical). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.

Which devices are affected by CVE-2021-47940?

The list of devices confirmed to be affected by CVE-2021-47940 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.

How do I fix or mitigate CVE-2021-47940?

Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.