What is CVE-2021-20842?

CVE-2021-20842 is a medium-severity vulnerability in Ec-Cube, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2021-11-24.

How severe is CVE-2021-20842?

Medium severity. CVSS v3 base score is 6.5 out of 10.

CSRF in Ec-Cube

CVE-2021-20842

Cross-site request forgery (CSRF) vulnerability in EC-CUBE 2 series 2.11.0 to 2.17.1 allows a remote attacker to hijack the authentication of Administrator and delete Administrator via a specially crafted web page.

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2021-11-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.006 (44.1th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.000

Affected products

Ec-Cube
Ec-Cube Co.,ltd. 2 Series — versions 2.11.0 to 2.17.1

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

www.ec-cube.net/info/weakness/20211111/ (Exploit, Patch, Vendor Advisory)
jvn.jp/en/jp/JVN75444925/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-20842?: CVE-2021-20842 is a medium-severity vulnerability in Ec-Cube, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2021-11-24.
How severe is CVE-2021-20842?: Medium severity. CVSS v3 base score is 6.5 out of 10.