Fortinet has released urgent firmware updates for Fortigate devices to address a critical pre-authentication remote code execution (RCE) vulnerability in SSL VPNs. The security fixes were quietly released in FortiOS firmware versions 6.0.17, 6.2.15, 6.4.13, 7.0.12, and 7.2.5.
While the specific details of the vulnerability were not mentioned in the release notes, security professionals have hinted that it could allow attackers to interfere with VPN connections even if multi-factor authentication (MFA) is enabled. Researchers have identified the vulnerability as CVE-2023-27997 and have urged Fortinet administrators to apply the patch urgently, as the flaw is likely to be analyzed and exploited by threat actors.
Fortinet is known for releasing security patches before disclosing critical vulnerabilities to give customers time to update their devices and stay protected. Lexfo Security vulnerability researcher Charles Fol confirmed that the FortiOS updates include a fix for the critical RCE vulnerability that he and Rioru discovered.
Given that Fortinet devices are widely used in firewall and VPN solutions, with over 250,000 Fortigate firewalls accessible over the Internet, the majority of devices are likely exposed to the bug. In the past, SSL-VPN flaws have been exploited shortly after patches are released, making prompt patching crucial to prevent data theft and ransomware attacks.
Fortinet has been contacted for further information about the updates, but no response has been received at this time. Administrators are advised to promptly apply the security updates and stay vigilant to protect their networks from potential exploitation.
Fortinet emphasizes the importance of timely communication with customers and responsible disclosure practices to provide the necessary information for informed risk-based decisions.