Fortinet’s Warning: Exploitation of Five-Year-Old Vulnerability
Fortinet recently alerted users about the active exploitation of a five-year-old vulnerability in its FortiOS SSL VPN, identified as CVE-2020-12812. This flaw allows attackers to bypass two-factor authentication under specific configurations, raising alarms for IT infrastructure professionals.
Key Details
- Who: Fortinet
- What: CVE-2020-12812, an improper authentication vulnerability, affecting FortiOS SSL VPN.
- When: Latest advisory issued on December 24, 2025; vulnerability first disclosed in July 2020.
- Where: Applicable to FortiGate devices using FortiOS.
- Why: The vulnerability allows unauthorized access by mismanaging username case sensitivity between local and remote user authentications.
- How: If a username is entered with varying cases (e.g., "Jsmith" vs. "jsmith"), it may lead to successful authentication without required second-factor verification.
Why It Matters
The implications of this vulnerability are significant, especially for organizations dealing with:
- Enterprise Security: Improper authentication opens doors for unauthorized access, heightening security risks for admin accounts and VPN users.
- Hybrid/Multi-Cloud Adoption: Organizations utilizing FortiOS within cloud environments must rethink their authentication strategies to avoid exploitation.
- Server/Network Automation: Unpatched systems could lead to automation failures due to unauthorized access.
Takeaway for IT Teams
IT professionals should immediately review their FortiGate configurations, ensuring they are using FortiOS versions 6.0.10, 6.2.4, 6.4.1, or later. It’s crucial to disable username case sensitivity to safeguard against this authentication bypass vulnerability. Regularly monitor for any signs of unauthorized access and engage with Fortinet support if any discrepancies are noted.
For ongoing updates and insights on IT infrastructure, visit TrendInfra.com.
