CVE-2019-6693: Fortinet FortiOS Use of Hard-Coded Credentials Vulnerability
Fortinet · FortiOS · NVD published 2019-11-21 · posted 2025-06-25 · last modified 2026-08-04
What it is
Use of a hard-coded cryptographic key to cipher sensitive data in FortiOS configuration backup file may allow an attacker with access to the backup file to decipher the sensitive data, via knowledge of the hard-coded key. The aforementioned sensitive data includes users' passwords (except the administrator's password), private keys' passphrases and High Availability password (when set).
| Weakness | CWE-798 |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N (source: [email protected]) |
| CISA due date | 2025-07-16 (for US federal agencies under BOD; a good deadline for everyone) |
| ATT&CK tactics | Initial Access → Persistence → Privilege Escalation → Stealth |
Exploitation evidence
First exploit evidence seen: 2021-12-21 (earliest date across the sources below).
Exploited in the wild
- CISA KEV: listed since 2025-06-25. Source
Public exploit code
GitHub proof-of-concept repositories
4 public repositories from 4 accounts, first seen 2021-12-21. Most starred: saladandonionrings/cve-2019-6693 (30 stars), view repository.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: CISA KEV · nomi-sec/PoC-in-GitHub.
Defend the Chain
The attack chain for CVE-2019-6693 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.
Pick a red technique card on the board, then choose the defence that stops it.
Defend against T1078.001 Default Accounts Inferred
Inferred from CWE CWE-798
How to fix it
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (source: CISA KEV)
Fixed versions
- fortinet fortios: versions up to and including 5.6.10 are affected; check the vendor advisory for the fixed release.
- fortinet fortios: versions up to and including 6.0.6 are affected; check the vendor advisory for the fixed release.
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://fortiguard.com/advisory/FG-IR-19-007 (CISA KEV notes)
MITRE ATT&CK mitigations for this chain
- M1032 Multi-factor Authentication (for T1078.001) : Implement multi-factor authentication (MFA) for default accounts whenever possible to prevent unauthorized access, even if credentials for these accounts are compromised. MFA adds an additional layer of security that requires more than just a username and password, making it significantly harder for adversaries to expl
- M1027 Password Policies (for T1078.001) : Applications and appliances that utilize default username and password should be changed immediately after the installation, and before deployment to a production environment.
Detection Generic guidance
- Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
- Persistence: Look for new files in web roots, new scheduled tasks/services, and new accounts created after the exposure window.
- Privilege Escalation: Alert on processes gaining SYSTEM/root unexpectedly, and on exploitation crashes of privileged services.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.