CVE-2019-5591
Fortinet FortiOS Default Configuration Vulnerability
MITRE ATT&CK techniques
How this vulnerability maps to adversary behaviour, from the Center for Threat-Informed Defense's public CVE→ATT&CK mappings. Use it to check whether your detections already cover the technique.
Summary
Fortinet FortiOS contains a default configuration vulnerability that may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the Lightweight Directory Access Protocol (LDAP) server.
Affected software
Vendor: Fortinet · Product: FortiOS
Weakness types (CWE):
What to do
This vulnerability appears in CISA's Known Exploited Vulnerabilities catalog, meaning it is being exploited in the wild. Prioritize patching affected systems and verify exposure across your estate.
Related vulnerabilities in Fortinet
| CVE | Name | EPSS | Exploited |
|---|---|---|---|
| CVE-2018-13379 | Fortinet FortiOS SSL VPN Path Traversal Vulnerability | 100.0% | Yes |
| CVE-2022-40684 | Fortinet Multiple Products Authentication Bypass Vulnerability | 100.0% | Yes |
| CVE-2025-25257 | Fortinet FortiWeb SQL Injection Vulnerability | 99.9% | Yes |
| CVE-2022-42475 | Fortinet FortiOS Heap-Based Buffer Overflow Vulnerability | 99.5% | Yes |
| CVE-2023-48788 | Fortinet FortiClient EMS SQL Injection Vulnerability | 98.4% | Yes |
| CVE-2026-21643 | Fortinet FortiClient EMS SQL Injection Vulnerability | 97.7% | Yes |
| CVE-2024-47575 | Fortinet FortiManager Missing Authentication Vulnerability | 94.8% | Yes |
| CVE-2024-55591 | Fortinet FortiOS and FortiProxy Authentication Bypass Vulnerability | 94.4% | Yes |
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