CVE-2021-3355

Name: CVE-2021-3355
Creator: NVD / NIST
Published: 2021-02-24T15:15:13.933+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 7.28%

Last modified Jun 17, 2026

CVE-2021-3355 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. A stored-self XSS exists in LightCMS v1.3.4, allowing an attacker to execute HTML or JavaScript code in a vulnerable Title field to /admin/SensitiveWords.. EPSS estimates a 7.28% chance of exploitation in the next 30 days.

Description

A stored-self XSS exists in LightCMS v1.3.4, allowing an attacker to execute HTML or JavaScript code in a vulnerable Title field to /admin/SensitiveWords.

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

7.28%

93.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Lightcms Project	Lightcms	1.3.4

References

http://packetstormsecurity.com/files/161562/LightCMS-1.3.4-Cross-Site-Scripting.htmlExploit, Third Party Advisory, VDB Entry
https://gist.github.com/Peithon/1c628ded0c4fc96c6331c3cce1d0c69bExploit, Third Party Advisory
https://github.com/eddy8/LightCMS/issues/18Exploit, Issue Tracking, Third Party Advisory
https://www.exploit-db.com/exploits/49598Exploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/161562/LightCMS-1.3.4-Cross-Site-Scripting.htmlExploit, Third Party Advisory, VDB Entry
https://gist.github.com/Peithon/1c628ded0c4fc96c6331c3cce1d0c69bExploit, Third Party Advisory
https://github.com/eddy8/LightCMS/issues/18Exploit, Issue Tracking, Third Party Advisory
https://www.exploit-db.com/exploits/49598Exploit, Third Party Advisory, VDB Entry

Timeline

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

Frequently Asked Questions

What is CVE-2021-3355?

A stored-self XSS exists in LightCMS v1.3.4, allowing an attacker to execute HTML or JavaScript code in a vulnerable Title field to /admin/SensitiveWords.

How severe is CVE-2021-3355?

CVE-2021-3355 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 7.28% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3355?

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-2021-3355?

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

Scan your code now

Source: NVD / NIST