FortiOS Hard-Coded Credential Vulnerability (CVE-2019-6693)

Historical catalog analysis: CISA added this entry on June 25, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2019-6693 is a vulnerability in Fortinet FortiOS involving the use of hard-coded credentials (CWE-798). Specifically, the system utilizes a hard-coded key to encrypt configuration backup files. An attacker with knowledge of this key could potentially decipher sensitive data contained within those backups.

Exposure and applicability

This vulnerability affects deployments of Fortinet FortiOS that utilize the impacted encryption mechanism for configuration backups. The risk is elevated because this flaw has been identified as having known use in ransomware campaigns. Organizations maintaining offline or cloud-stored configuration backups are particularly exposed if those files are accessed by an unauthorized party.

Remediation priorities

Based on the reported vulnerability, our analysis suggests the following prioritization for vulnerability management teams:

1. Identify and Update Affected Assets: Prioritize the identification of all FortiOS devices in the environment. Apply vendor-provided mitigations or updates as specified in the official advisory to replace or secure the encryption mechanism.
2. Secure Backup Storage: Since the vulnerability targets backup files, restrict access to configuration backups using strict identity and access management (IAM) controls to prevent attackers from obtaining the files necessary for decryption.
3. Review Cloud Service Exposure: For organizations utilizing cloud services, follow applicable BOD 22-01 guidance to ensure that FortiOS instances are not exposing sensitive configurations in shared or insecure cloud environments.
4. Decommission Unpatchable Assets: If a specific legacy version of the product cannot be mitigated according to vendor instructions, our analysis recommends discontinuing use of that asset to eliminate the exposure path.

How to validate remediation

Verification must go beyond a simple version check, as a patched binary does not automatically secure previously created backup files. To verify that exposure has been reduced, defenders should:

• Confirm Mitigation Application: Verify through vendor-approved methods that the updated encryption logic is active on the device.
• Audit Backup Integrity: Identify all existing configuration backups created prior to the mitigation and determine if they were encrypted with the hard-coded key. These legacy files may still be vulnerable even after the system is patched.
• Validate Access Controls: Perform an authorized audit of the storage locations for these backups to ensure that only authorized administrative roles have access, thereby limiting the ability of an attacker to apply the known key to a captured file.

Limits and open questions

A primary limitation of this remediation is the persistence of risk in legacy data. Applying a patch to the FortiOS firmware may prevent new backups from using the hard-coded key, but it does not retroactively re-encrypt old backup files already stored in archives or cloud storage. The residual risk remains that any previously exfiltrated or stored backup file remains decipherable by anyone possessing the hard-coded key.

Source and editorial note

CVE-2019-6693: Fortinet FortiOS Use of Hard-Coded Credentials Vulnerability · Source date: June 25, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: June 28, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 10, 2026 at 00:41 UTC.

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