CVE-2021-41566

Name: CVE-2021-41566
Creator: NVD / NIST
Published: 2021-10-08T16:15:07.947+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.94%

Last modified Jun 17, 2026

CVE-2021-41566 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. The file extension of the TadTools file upload function fails to filter, thus remote attackers can upload any types of files and execute arbitrary code without logging in.. EPSS estimates a 1.94% chance of exploitation in the next 30 days.

Description

The file extension of the TadTools file upload function fails to filter, thus remote attackers can upload any types of files and execute arbitrary code without logging in.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

1.94%

77.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Tadtools Project	Tadtools	< 3.2.2

References

https://www.twcert.org.tw/tw/cp-132-5170-83472-1.htmlThird Party Advisory
https://www.twcert.org.tw/tw/cp-132-5170-83472-1.htmlThird Party Advisory

Timeline

Published: Oct 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41566?

The file extension of the TadTools file upload function fails to filter, thus remote attackers can upload any types of files and execute arbitrary code without logging in.

How severe is CVE-2021-41566?

CVE-2021-41566 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.94% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41566?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-41566?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST