CVE-2019-17659
Published: 17 March 2025
Summary
CVE-2019-17659 is a low-severity Use of Hard-coded Credentials (CWE-798) vulnerability in Fortinet Fortisiem. Its CVSS base score is 3.7 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique External Remote Services (T1133); ranked in the top 33.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 IA-5 (Authenticator Management) and SC-12 (Cryptographic Key Establishment and Management).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
SC-12 requires establishment and management of cryptographic keys, directly preventing the use of hard-coded private keys that enable unauthorized SSH access.
IA-5 mandates secure management of authenticators including SSH private keys, ensuring they are not hard-coded or default and are properly generated and protected.
AC-17 enforces authorization and protection mechanisms for remote access like SSH, limiting exposure to hard-coded key exploitation on the supervisor component.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Hardcoded private key enables remote unauthenticated SSH access to supervisor as tunneluser, directly facilitating initial access via external remote services.
NVD Description
A use of hard-coded cryptographic key vulnerability in FortiSIEM version 5.2.6 may allow a remote unauthenticated attacker to obtain SSH access to the supervisor as the restricted user "tunneluser" by leveraging knowledge of the private key from another installation or…
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a firmware image.
Deeper analysisAI
CVE-2019-17659 is a use of hard-coded cryptographic key vulnerability (CWE-798) in FortiSIEM version 5.2.6. The issue stems from a hard-coded private key that enables SSH access to the supervisor component as the restricted user "tunneluser".
A remote unauthenticated attacker can exploit this vulnerability by leveraging knowledge of the private key obtained from another FortiSIEM installation or a firmware image. Successful exploitation grants SSH access to the supervisor as "tunneluser", with a CVSS v3.1 base score of 3.7 (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L), reflecting high attack complexity and primarily low availability impact.
Mitigation details are available in the Fortinet PSIRT advisory FG-IR-19-296 at https://fortiguard.fortinet.com/psirt/FG-IR-19-296.
Details
- CWE(s)