The Cybersecurity and Infrastructure Security Agency (CISA) has recently highlighted a critical vulnerability in Fortinet’s FortiOS operating system, identified as CVE-2019-6693. This flaw involves the use of hard-coded encryption keys within FortiOS configuration backup files, potentially allowing unauthorized access to sensitive data.
Understanding CVE-2019-6693
CVE-2019-6693 pertains to a security weakness where FortiOS employs static, hard-coded cryptographic keys to encrypt configuration backup files. If an attacker gains access to these backup files, they can use the known encryption key to decrypt and retrieve sensitive information, including user credentials (excluding the administrator’s password), private key passphrases, and High Availability (HA) passwords. This vulnerability is classified under CWE-798, which denotes the use of hard-coded credentials—a practice that poses significant security risks.
Implications of the Vulnerability
The presence of hard-coded credentials in security systems like FortiOS is particularly concerning because it creates a predictable attack vector. Once the hard-coded key is known, any individual with access to the backup files can decrypt them, leading to potential unauthorized access to network configurations and sensitive data. This undermines the confidentiality and integrity of the network infrastructure, making it susceptible to further exploitation.
CISA’s Response and Recommendations
On June 25, 2025, CISA added CVE-2019-6693 to its Known Exploited Vulnerabilities (KEV) catalog, indicating active exploitation of this vulnerability in real-world scenarios. In response, CISA has mandated that organizations using affected Fortinet FortiOS systems implement necessary mitigations by July 16, 2025. This directive aligns with federal cybersecurity guidelines aimed at proactively addressing vulnerabilities that pose significant threats to national security and critical infrastructure.
Mitigation Strategies
To address this vulnerability, organizations should take the following steps:
1. Update FortiOS: Ensure that all FortiOS devices are updated to the latest firmware versions where this vulnerability has been patched.
2. Encrypt Backup Files: When creating configuration backups, enable encryption and use strong, unique passwords to protect the backup files.
3. Secure Storage: Store backup files in secure locations with restricted access to prevent unauthorized retrieval.
4. Regular Audits: Conduct regular security audits to identify and remediate potential vulnerabilities within the network infrastructure.
5. Monitor for Exploitation: Implement monitoring mechanisms to detect any attempts to exploit this vulnerability within your network.
Broader Context of Hard-Coded Credentials in Fortinet Products
This is not the first instance where Fortinet products have been found to contain hard-coded credentials. Previous vulnerabilities include:
– CVE-2023-33304: A hard-coded credentials issue in FortiClient for Windows versions 7.0.0 to 7.0.9 and 7.2.0 to 7.2.1, allowing attackers to bypass system protections.
– CVE-2021-26108: A hard-coded cryptographic key vulnerability in the SSLVPN component of FortiOS versions before 7.0.1, potentially enabling attackers to retrieve the key through reverse engineering.
– CVE-2021-32588: A hard-coded credentials vulnerability in FortiPortal versions 5.2.5 and below, 5.3.5 and below, and 6.0.4 and below, allowing remote unauthenticated attackers to execute unauthorized commands as root.
These recurring issues underscore the importance of eliminating hard-coded credentials in software development to enhance security.
Conclusion
The identification and active exploitation of CVE-2019-6693 serve as a critical reminder of the risks associated with hard-coded credentials in security systems. Organizations utilizing Fortinet FortiOS must take immediate action to mitigate this vulnerability by updating their systems, securing backup files, and adhering to best practices for credential management. Proactive measures are essential to safeguard sensitive information and maintain the integrity of network infrastructures.
