FortiClient VPN 7.4.2.1737

Security Questions and Known Issues with FortiClient VPN

1. Have there been any significant security breaches involving FortiClient VPN?

Yes, FortiClient VPN has been associated with several security incidents. Notably, in early 2025, a hacking group leaked configuration files and VPN credentials for over 15,000 FortiGate devices, which are often managed using FortiClient. This breach exposed sensitive information, including IP addresses and VPN credentials, posing significant risks to affected organizations.
Read more at Bleeping Computer

Additionally, in 2024, Chinese threat actors exploited a zero-day vulnerability in FortiClient's Windows VPN client using a custom toolkit named "DeepData" to steal credentials. This vulnerability allowed attackers to dump credentials from memory after user authentication.
Full report at Bleeping Computer

2. What are some known vulnerabilities in FortiClient VPN?

Several vulnerabilities have been identified in FortiClient VPN over the years. For instance, CVE-2024-21762 is an out-of-bounds write vulnerability in the SSL VPN daemon of Fortinet FortiOS, which could allow unauthenticated remote attackers to execute arbitrary code.
Details from Tenable

Another vulnerability, CVE-2024-50570, involves the cleartext storage of sensitive information in FortiClient for Windows and Linux. This flaw could permit a local authenticated user to retrieve VPN passwords via memory dump, posing a significant security risk.
Advisory at FortiGuard

3. Are there any recurring issues or bugs reported by users?

Yes, users have reported various issues across different versions of FortiClient. For example, in version 7.4.0, installing FortiClient caused blue screen of death (BSOD) errors due to conflicts with certain system drivers.
FortiClient 7.4.0 Windows Release Notes

In version 7.2.8, users experienced problems with IPsec VPN connections, including failures and disconnections for groups of users, and issues with subnet exclusion not working properly in dialup IPsec VPN.
FortiClient 7.2.8 Release Notes

4. How can users mitigate these security risks?

To mitigate security risks associated with FortiClient VPN, users should follow these best practices:

• Regularly Update Software: Ensure that FortiClient and FortiOS are updated to the latest versions to benefit from security patches.
• Monitor Official Advisories: Stay informed by regularly checking Fortinet’s PSIRT Advisories for the latest security updates and patches.
• Implement Strong Authentication: Use multi-factor authentication (MFA) to add an extra layer of security to VPN access.
• Limit Access: Restrict VPN access to necessary users and monitor for unusual activity.
• Regularly Review Configurations: Audit VPN configurations and credentials to ensure they have not been compromised.

While FortiClient VPN offers robust security features, it is essential for users and administrators to stay vigilant, keep software up to date, and follow best practices to mitigate potential risks.

For more detailed information on known issues and vulnerabilities, refer to Fortinet’s official documentation and FortiGuard advisories.