Cyber Resilience

CVE-2021-26637

High

Published: 23 June 2022

Published
23 June 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0034 56.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-26637 is a high-severity Improper Authentication (CWE-287) vulnerability in Shinasys Sihas Sgw-300 Firmware. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 43.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

shinasys
sihas sgw-300 firmware
all versions
shinasys
sihas acm-300 firmware
all versions
shinasys
sihas gcm-300 firmware
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

Session content review can reveal authentication bypasses or failures in session establishment.

Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.

Identity providers centralize and enforce authentication mechanisms, reducing improper authentication.

Personnel screening, identity verification, and access-agreement requirements support reliable authentication and reduce authentication bypass opportunities.

Decoy authentication surfaces detect bypass attempts and deflect real credential attacks through observable malicious interactions.

addresses: CWE-306 CWE-862

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

addresses: CWE-306 CWE-862

Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.

addresses: CWE-862 CWE-306

Always invoking the reference monitor prevents missing authorization checks for protected resources.

References