What is CVE-2021-42331?

CVE-2021-42331 is a medium-severity vulnerability in Shinher Information Co., Ltd. Studyonline System, classified under Improper Authorization. CVSS score: 5.4/10. Published 2021-10-15.

How severe is CVE-2021-42331?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Shinher Information Co., Ltd. Studyonline System

CVE-2021-42331

The “Study Edit” function of ShinHer StudyOnline System does not perform permission control. After logging in with user’s privilege, remote attackers can access and edit other users’ tutorial schedule by crafting URL parameters.

Published 2021-10-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (48.8th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Shinher Information Co., Ltd. Studyonline System — versions unspecified
Xinheinformation Xinhe Teaching Platform System — versions v2021

Weakness classification (CWE)

References

www.twcert.org.tw/tw/cp-132-5201-dc534-1.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-42331?: CVE-2021-42331 is a medium-severity vulnerability in Shinher Information Co., Ltd. Studyonline System, classified under Improper Authorization. CVSS score: 5.4/10. Published 2021-10-15.
How severe is CVE-2021-42331?: Medium severity. CVSS v3 base score is 5.4 out of 10.