CVE-2021-27309

Name: CVE-2021-27309
Creator: NVD / NIST
Published: 2021-03-23T14:15:13.337+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.98%

Last modified Jun 17, 2026

CVE-2021-27309 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Clansphere CMS 2011.4 allows unauthenticated reflected XSS via "module" parameter.. EPSS estimates a 1.98% chance of exploitation in the next 30 days.

Description

Clansphere CMS 2011.4 allows unauthenticated reflected XSS via "module" parameter.

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

1.98%

78.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Csphere	Clansphere	2011.4

References

https://github.com/xoffense/POC/blob/main/Clansphere%202011.4%20%22module%22%20xss.mdExploit, Third Party Advisory
https://github.com/xoffense/POC/blob/main/Clansphere%202011.4%20%22module%22%20xss.mdExploit, Third Party Advisory

Timeline

Published: Mar 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27309?

Clansphere CMS 2011.4 allows unauthenticated reflected XSS via "module" parameter.

How severe is CVE-2021-27309?

CVE-2021-27309 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.98% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27309?

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-2021-27309?

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

Scan your code now

Source: NVD / NIST