Fortinet FortiOS contains a use of hard-coded credentials vulnerability that could allow an attacker to cipher sensitive data in FortiOS configuration backup file via knowledge of the hard-coded key.
FREQUENTLY ASKED
What is CVE-2019-6693 and why does it matter?
CVE-2019-6693 is a vulnerability in Fortinet FortiOS where a hard-coded cryptographic key is used to cipher sensitive data in configuration backup files. It matters because an attacker with access to the backup can use this known key to decipher sensitive information, including user passwords and private keys, potentially leading to a full network compromise.
Which versions of Fortinet FortiOS are affected by this vulnerability?
Based on the official data, the affected versions of Fortinet FortiOS include version 5.6.9 and below, version 6.0.5 and below, and version 6.2.0. If your deployment is running any of these legacy versions, you are currently at risk and should seek an immediate upgrade to a patched release.
Has a patch been released for CVE-2019-6693?
Yes, Fortinet has released security updates to address this issue. Administrators should refer to the official FortiGuard advisory FG-IR-19-007 for specific fixed versions. Remediation involves upgrading to a firmware version that no longer utilizes the vulnerable hard-coded cryptographic mechanism for backup file security.
What is the remediation deadline and what does it mean for compliance?
The remediation deadline is set for 2025-07-16. For organizations following CISA BOD 22-01 or similar federal mandates, this date is a strict requirement for applying mitigations. Failure to patch by this date may result in non-compliance and elevated risk exposure, especially given the known ransomware use associated with this vulnerability.
How can I check if my FortiOS instance is affected?
To check if your deployment is affected, log into your FortiOS management console and verify the current firmware version. If the version is 5.6.9 or lower, 6.0.5 or lower, or exactly 6.2.0, your instance is vulnerable. You should also audit your backup storage policies to ensure unauthorized actors cannot access current or historical configuration files.
CVE-2019-6693 identifies a critical weakness in the way Fortinet FortiOS handles sensitive data within its configuration backup mechanism. With a CVSS score of 6.5 and a high EPSS score of 0.72223, this vulnerability represents a significant risk to network integrity. The core of the issue lies in the use of a hard-coded cryptographic key (CWE-798) to encrypt sensitive configuration data. If an attacker gains access to a backup file, they can leverage this hard-coded key to decipher passwords and private keys, bypassing intended security controls. Given the active exploitation status and known ransomware usage, immediate remediation by the 2025-07-16 deadline is mandatory for maintaining a secure defensive posture.
Vulnerability Profile Table
Field
Value
CVE ID
CVE-2019-6693
Affected Product & Versions
5.6.9 and below, 6.0.5 and below, 6.2.0
CVSS Score & Severity
6.5 (MEDIUM)
CVSS Version
3.1
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
CWE IDs
CWE-798
Date Disclosed
2025-06-25
Remediation Deadline
2025-07-16
SSVC Exploitation status
active
Known Ransomware Use
Known
EPSS Score & Percentile
0.72223 (98.8%)
Patch Available
Yes
Technical Deep Dive: The Risks of Hard-Coded Cryptography
The vulnerability in FortiOS stems from a fundamental violation of cryptographic principles: the reliance on static, shared secrets for data protection. In the context of CVE-2019-6693, the specific issue is classified under CWE-798: Use of Hard-coded Credentials. While often associated with administrative passwords, CWE-798 in this instance refers to the use of a hard-coded cryptographic key embedded within the firmware itself.
Understanding CWE-798: Use of Hard-coded Credentials
Cryptographic security relies on the secrecy of the key, not the algorithm. When a vendor embeds a cryptographic key directly into the software's binary or source code, that key becomes effectively public once the software is distributed. Any researcher or malicious actor who reverse-engineers the firmware can extract the key.
In FortiOS, this key was used to "cipher" or obfuscate sensitive entries within the configuration backup file. These files are typically exported for disaster recovery or configuration auditing purposes. By using a hard-coded key, Fortinet inadvertently allowed anyone with the key and the backup file to reverse the encryption, turning seemingly unreadable strings back into plaintext credentials. This is analogous to a bank using a master key that is printed in the user manual for every safe they sell.
The Backup Deciphering Attack Chain
The attack chain for CVE-2019-6693 requires two primary components: access to a configuration backup file and knowledge of the static key. The attack vector is classified as NETWORK with LOW complexity, meaning an attacker does not need sophisticated tools to achieve their goal once the prerequisites are met.
Access Acquisition: The attacker must first obtain a FortiOS configuration backup file. This might occur through unauthorized access to a management server, intercepting backups transferred over insecure protocols (like unencrypted TFTP or FTP), or exploiting other vulnerabilities (such as directory traversal) that allow for file extraction from the FortiGate appliance.
Key Application: Using the hard-coded key—which has been publicly documented by security researchers since the disclosure of this vulnerability—the attacker applies a decryption utility against the backup file.
Data Extraction: The attacker successfully deciphers sensitive fields. The Full Description notes that this includes user passwords (excluding the primary administrator's password), private keys' passphrases, and High Availability (HA) passwords.
Attack Surface and Blast Radius
The attack surface for this vulnerability is not the firewall's external interface directly, but rather the entire lifecycle of its configuration backups. The blast radius is significant; gaining the HA password allows an attacker to potentially interfere with the failover mechanisms of a security cluster. More critically, the disclosure of private key passphrases could allow an attacker to impersonate the organization's infrastructure in encrypted communications, leading to a total loss of confidentiality across the network.
Who Is Affected: Identifying the Impacted Perimeter
This vulnerability impacts a wide range of legacy Fortinet deployments. Organizations that have not updated their perimeter defenses in several years are at the highest risk. Specifically, any device running FortiOS versions 5.6.9, 6.0.5, or 6.2.0 (and their respective earlier iterations) contains the hard-coded key logic.
Compliance and CISA BOD 22-01 Requirements
CVE-2019-6693 is listed in the CISA Known Exploited Vulnerabilities (KEV) Catalog. This inclusion is due to evidence of active exploitation by threat actors, including ransomware groups. Under Binding Operational Directive (BOD) 22-01, Federal Civilian Executive Branch (FCEB) agencies are required to remediate this vulnerability within the specified timeframe.
For the broader private sector, the remediation deadline of 2025-07-16 serves as a critical benchmark. Organizations subject to PCI-DSS, HIPAA, or SOC2 audits should consider this vulnerability a high-priority finding. Because the vulnerability involves the disclosure of authentication secrets and private keys, failing to patch can be seen as a failure to protect "sensitive data at rest," which is a core tenant of most compliance frameworks.
Official Remediation Steps
Remediation for CVE-2019-6693 focuses on transitioning away from the vulnerable firmware versions to releases that implement dynamic, unique, or user-defined cryptographic keys for backup files.
Identify Vulnerable Assets: Use the FortiManager or individual device dashboards to inventory the firmware versions of all FortiGate appliances. Focus on identifying versions 5.6.x, 6.0.x, and 6.2.0.
Consult Official Advisory: Visit the FortiGuard Advisory FG-IR-19-007 to determine the exact upgrade path for your hardware models.
Perform Firmware Upgrade: Apply the following minimum versions to resolve the issue:
Upgrade FortiOS 5.6.x to 5.6.10 or higher.
Upgrade FortiOS 6.0.x to 6.0.6 or higher.
Upgrade FortiOS 6.2.0 to 6.2.1 or higher.
Rotate Compromised Secrets: Simply patching the firmware does not secure the passwords that were previously "protected" by the hard-coded key. After upgrading, administrators must rotate all passwords and private key passphrases that were stored in the previous configuration backups.
Secure Legacy Backups: Delete or securely encrypt historical configuration backup files that were generated prior to the patch, as these files remain vulnerable to decryption using the hard-coded key.
Security Best Practices for Configuration Management
To prevent the recurrence of similar cryptographic failures and to harden the environment against the exploitation of configuration files, implement the following best practices:
Encrypt Backups with Unique Keys: When exporting a configuration backup, always use the option to encrypt the file with a strong, unique passphrase. This adds a layer of encryption that is independent of the system's internal hard-coded mechanisms.
Use Secure Transfer Protocols: Never use TFTP or unencrypted FTP to move configuration backups. Utilize SCP (Secure Copy Protocol) or HTTPS to ensure that even if a file is intercepted, it is protected by TLS/SSH encryption.
Implement Role-Based Access Control (RBAC): Restrict the ability to perform configuration backups to a limited number of high-privileged administrators. Audit every instance of a configuration export.
Centralized Secrets Management: Move away from storing static passwords in configuration files where possible. Integrate the firewall with centralized authentication systems like LDAP, RADIUS, or SAML, which utilize dynamic authentication tokens.
MFA for Management Access: Ensure that all administrative access to the FortiOS CLI and Web UI requires Multi-Factor Authentication (MFA), reducing the impact of a deciphered password.
Regular Firmware Audits: Establish a routine cadence for reviewing CISA KEV updates and vendor advisories to ensure that