Cyber Resilience

CVE-2023-26208

Low

Published: 09 March 2023

Published
09 March 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.1970 95.6th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-26208 is a low-severity Improper Restriction of Excessive Authentication Attempts (CWE-307) vulnerability in Fortinet Fortiauthenticator. Its CVSS base score is 3.7 (Low).

Operationally, ranked in the top 4.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

CVE-2023-26208 is an improper restriction of excessive authentication attempts vulnerability, tracked as CWE-307, that affects Fortinet FortiAuthenticator versions 6.4.x and earlier. The flaw resides in the login form and permits a remote attacker to submit repeated HTTP requests that partially exhaust CPU and memory resources on the affected system. Its CVSS 3.1 base score is 3.7, reflecting network attack vector, high attack complexity, and limited impact on availability.

A remote unauthenticated attacker can exploit the weakness simply by generating numerous HTTP requests against the login form, resulting in partial resource exhaustion without any authentication or user interaction required.

The official FortiGuard advisory FG-IR-20-078, referenced at https://fortiguard.com/psirt/FG-IR-20-078, addresses the issue for supported FortiAuthenticator releases. The EPSS score remains flat at 0.1970 with no material increase after disclosure.

EU & UK References

Vulnerability details

A improper restriction of excessive authentication attempts vulnerability [CWE-307] in Fortinet FortiAuthenticator 6.4.x and before allows a remote unauthenticated attacker to partially exhaust CPU and memory via sending numerous HTTP requests to the login form.

CWE(s)

Related Threats

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

Affected Assets

fortinet
fortiauthenticator
5.4.0 — 6.5.0

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.

addresses: CWE-307

This control directly enforces limits on consecutive invalid logon attempts and automatic response (e.g., lockout) to prevent brute-force exploitation of authentication mechanisms.

addresses: CWE-307

Specific conditions can include excessive failed attempts, triggering stronger authentication that restricts brute-force exploitation.

References