What is CVE-2020-27409?

CVE-2020-27409 is a medium-severity vulnerability in Os4ed Opensis, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-12-04.

How severe is CVE-2020-27409?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Os4ed Opensis

CVE-2020-27409

OpenSIS Community Edition before 7.5 is affected by a cross-site scripting (XSS) vulnerability in SideForStudent.php via the modname parameter.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-12-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (66.9th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Os4ed Opensis

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/OS4ED/openSIS-Responsive-Design/commit/edca0855e7bc27d5b28dcb2d16f05… (Patch, Third Party Advisory)
github.com/OS4ED/openSIS-Responsive-Design/compare/ver7.4...V7.5 (Third Party Advisory)
insinuator.net/2020/10/opensis-vulnerabilities/ (Third Party Advisory)

Frequently asked questions

What is CVE-2020-27409?: CVE-2020-27409 is a medium-severity vulnerability in Os4ed Opensis, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-12-04.
How severe is CVE-2020-27409?: Medium severity. CVSS v3 base score is 6.1 out of 10.