What is CVE-2021-26637?

CVE-2021-26637 is a high-severity vulnerability in Shinasys Sihas Acm-300, classified under Improper Authentication. CVSS score: 8.8/10. Published 2022-06-23.

How severe is CVE-2021-26637?

High severity. CVSS v3 base score is 8.8 out of 10.

Auth bypass in Shinasys Sihas Acm-300

CVE-2021-26637

There is no account authentication and permission check logic in the firmware and existing apps of SiHAS's SGW-300, ACM-300, GCM-300, so unauthorized users can remotely control the device.

Vulnerability class: Broken Authentication

Published 2022-06-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.019 (78.5th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.018 · newest: 0.019 · change: +0.001

Affected products

Shinasys Sihas Acm-300
Shinasys Sihas Acm-300 Firmware
Shinasys Sihas Gcm-300
Shinasys Sihas Gcm-300 Firmware
Shinasys Sihas Sgw-300
Shinasys Sihas Sgw-300 Firmware
Shina System Co.,ltd Sihas Firmware — versions 1.xx
Shina System Co.,ltd Sihas Old App — versions old app

Weakness classification (CWE)

References

www.krcert.or.kr/krcert/secNoticeView.do (VDB Entry, Third Party Advisory, Broken Link)

Frequently asked questions

What is CVE-2021-26637?: CVE-2021-26637 is a high-severity vulnerability in Shinasys Sihas Acm-300, classified under Improper Authentication. CVSS score: 8.8/10. Published 2022-06-23.
How severe is CVE-2021-26637?: High severity. CVSS v3 base score is 8.8 out of 10.