CVE-2017-20234
Published: 03 April 2026
Summary
CVE-2017-20234 is a critical-severity Use of Hard-coded Credentials (CWE-798) vulnerability in Belden (inferred from references). Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 36.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 IA-5 (Authenticator Management) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2017-20234 is an authentication bypass vulnerability in GarrettCom Magnum 6K and 10K managed switches. The flaw stems from a hardcoded string within the authentication mechanism, enabling attackers to circumvent login controls and gain unauthorized access to administrative functions and sensitive switch configurations without valid credentials. Published on 2026-04-03, it is associated with CWE-798 (Use of Hard-coded Credentials) and carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), classifying it as critical.
Unauthenticated attackers with network access to the affected switches can exploit this vulnerability remotely with low complexity and no user interaction or privileges required. Successful exploitation grants full administrative access, allowing attackers to view, modify, or disrupt switch configurations, potentially leading to network compromise, data exposure, or service disruption.
Advisories provide guidance on mitigation, including details in the Belden Security Bulletin (MNS-6K-10K-GarrettCom-BSECV-2017-08) at https://assets.belden.com/m/114be964b4651983/original/Security-Bulletin-MNS-6K-10K-GarrettCom-BSECV-2017-08.pdf and the VulnCheck advisory at https://www.vulncheck.com/advisories/garrettcom-magnum-6k-and-10k-authentication-bypass-via-hardcoded-string. Security practitioners should consult these resources for patch availability, workarounds, and upgrade recommendations.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2017-18957
Vulnerability details
GarrettCom Magnum 6K and 10K managed switches contain an authentication bypass vulnerability that allows unauthenticated attackers to gain unauthorized access by exploiting a hardcoded string in the authentication mechanism. Attackers can bypass login controls to access administrative functions and sensitive…
more
switch configuration without valid credentials.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct remote authentication bypass on a network device management interface enables exploitation of a public-facing application for unauthorized admin access.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the CVE by requiring identification, reporting, and timely correction of the authentication bypass flaw through vendor patches or upgrades.
Prevents exploitation of hardcoded strings in authentication by mandating proper management, protection, and changes to authenticators, prohibiting hard-coded credentials.
Enforces secure configuration settings for authentication mechanisms on the switches to avoid reliance on vulnerable hardcoded bypass strings.