SiHAS Improper Authentication vulnerability

published 2022-06-22 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-13431

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.9%; EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits: 0; none known

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.

Exploit prediction

1.92% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

Shina System Co.,Ltd SiHAS firmware
Shina System Co.,Ltd SiHAS old app

Classification

Weakness

CWE-287 Improper Authentication
CWE-306 Missing Authentication for Critical Functionality
CWE-862 Missing Authorization

References

krcert.or.kr /krcert/secNoticeView.do?bulletin_writing_sequence=66782
broken-link, third-party-advisory, vdb-entry

Sources

CVE List CVE-2021-26637
NVD CVE-2021-26637

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary