CVE-2021-3921

Name: CVE-2021-3921
Creator: NVD / NIST
Published: 2021-11-13T09:15:06.893+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.43%

Last modified Jun 17, 2026

CVE-2021-3921 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. firefly-iii is vulnerable to Cross-Site Request Forgery (CSRF). EPSS estimates a 0.43% chance of exploitation in the next 30 days.

Description

firefly-iii is vulnerable to Cross-Site Request Forgery (CSRF)

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.43%

34.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-352

Affected Software

Vendor	Product	Versions
Firefly-Iii	Firefly Iii	< 5.6.3

References

https://github.com/firefly-iii/firefly-iii/commit/47fa9e39561a9ec9e210e4023d090a7b33381684Patch, Third Party Advisory
https://huntr.dev/bounties/724d3fd5-9f04-45c4-98d6-35a7d15468f5Exploit, Patch, Third Party Advisory
https://github.com/firefly-iii/firefly-iii/commit/47fa9e39561a9ec9e210e4023d090a7b33381684Patch, Third Party Advisory
https://huntr.dev/bounties/724d3fd5-9f04-45c4-98d6-35a7d15468f5Exploit, Patch, Third Party Advisory

Timeline

Published: Nov 13, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3921?

firefly-iii is vulnerable to Cross-Site Request Forgery (CSRF)

How severe is CVE-2021-3921?

CVE-2021-3921 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3921?

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-2021-3921?

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

Scan your code now

Source: NVD / NIST