CVE-2019-5591VulnerabilityPublished 11/03/2021Updated 10/24/2026
CVE-2019-5591: Fortinet FortiOS Default Configuration Vulnerability
Affects Fortinet FortiOSSource CISA KEV
Severity
HighNo CVSS score published yet
- Exploitation
Actively exploited – in CISA KEV since 11/03/2021
- KEV deadline
- 05/03/2022
- Ransomware
- Used in ransomware campaigns
- EPSS
- 18.6% chance of exploitation in 30 days – higher than 97% of CVEs
What to do
CISA required action
Apply updates per vendor instructions.
Description
CVE-2019-5591 is a vulnerability in Fortinet FortiOS default configuration that allows an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server. This vulnerability has been exploited in the wild and is known to be used in ransomware campaigns. It is classified as high severity due to the potential exposure of sensitive data and active exploitation.