CVE-2019-5591
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the...
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
6.5
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
- Record
CVE-2019-5591- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 3.3 Low
AV:A/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
CVE List
6.5
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
- Record
CVE-2019-5591- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
EUVDEUVD-2019-15166
6.5
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
- Record
EUVD-2019-15166- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p9g8-h33v-mg42
6.5
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the...
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
- Record
GHSA-p9g8-h33v-mg42- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-200, CWE-306
- Updated
- 2026-11-02
CISA KEV No score
Fortinet FortiOS Default Configuration Vulnerability
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.
- Record
CVE-2019-5591- Weakness
- CWE-306
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | ayewo/fortios-ldap-mitm-poc-CVE-2019-5591 | 2025-10-16 |
| Nuclei | FortiOS - Insecure LDAP Configuration Detection |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation, exploits | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, Nuclei, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-5591 is a medium vulnerability (CVSS 6.5) in Fortinet Fortios, published August 14, 2020. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 18.6%, the 97th percentile. No source names a fixed version.