CVE-2021-20723

Name: CVE-2021-20723
Creator: NVD / NIST
Published: 2021-05-24T04:15:14.947+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.78%

Last modified Jun 17, 2026

CVE-2021-20723 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Reflected cross-site scripting vulnerability in [MailForm01] free edition (versions which the last updated date listed at the top of descriptions in the program file is from 2014 December 12 to 2018 July 27) allows a remote attacker to inject an arbitrary script via unspecified vectors.. EPSS estimates a 0.78% chance of exploitation in the next 30 days.

Description

Reflected cross-site scripting vulnerability in [MailForm01] free edition (versions which the last updated date listed at the top of descriptions in the program file is from 2014 December 12 to 2018 July 27) allows a remote attacker to inject an arbitrary script via unspecified vectors.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.78%

51.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mailform01 Project	Mailform01	>= 2014-12-12, <= 2018-07-27

References

https://jvn.jp/en/jp/JVN53910556/index.htmlThird Party Advisory
https://www.php-factory.net/mail/01.phpProduct, Third Party Advisory
https://jvn.jp/en/jp/JVN53910556/index.htmlThird Party Advisory
https://www.php-factory.net/mail/01.phpProduct, Third Party Advisory

Timeline

Published: May 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-20723?

How severe is CVE-2021-20723?

CVE-2021-20723 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.78% probability of exploitation in the next 30 days.

How do I fix CVE-2021-20723?

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-2021-20723?

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

Scan your code now

Source: NVD / NIST