Fortinet Flaw from 2020 Resurfaces: How to Avoid an Unwelcome Surprise

Fortinet’s December 24, 2025, product security advisory is an important reminder that threat actors:

• Plan on reduced staffing levels during the holidays to launch attacks
• Often follow a path of least resistance – leveraging old, unpatched vulnerabilities to gain access to systems 

The post warns that attackers are exploiting an unpatched critical FortiOS vulnerability, CVE-2020-12812, from July 2020 to bypass multi-factor authentication (MFA) and gain access to accounts. The advisory also urges customers to confirm whether they are affected and explains how to mitigate risk by reconfiguring or upgrading to a current version.

Clearly, understanding these vulnerabilities within the context of your environment is urgent. However, it’s also clear that NetOps and SecOps teams are already stretched thin managing existing workloads. Almost half of perimeter-device vulnerabilities remained unresolved last year. 

BackBox’s vulnerability intelligence capabilities are designed to help you avoid unwelcome surprises. When vulnerabilities are disclosed, BackBox makes it easy to be proactive.

• Instantly know if a vulnerability is relevant to your specific network inventory 
• Prioritize remediation based on risk scoring of each vulnerability and device
• Close the loop between identification and remediation with minimal effort

Relevant Vulnerabilities

Using search, you can determine whether a vulnerability is relevant. For example, you can check which FortiGate firewalls and FortiOS versions are running in your environment and whether  the configurations of those products are affected. 

Risk-Based Prioritization 

BackBox assigns a risk score to each CVE and device. This risk score indicates the vulnerability’s impact on the network by considering several factors, including the severity (based on the CVSS score which is 5.2 for this CVE, i.e.,  medium), the ease of exploitation (e.g., whether a device is publicly facing), whether the CVEs are known to be exploited (Fortinet observed recent abuse on Dec. 24), the impact of the exploit (in this case, the ability to unlock email, files, calendars, and internal collaboration by abusing legitimate OAuth logins), and so on. 

In summary, BackBox helps track vulnerabilities, determine which are relevant, and then, among those relevant, helps assess the potential severity of the vulnerabilities, so you can prioritize remediation.

Closed-Loop Remediation

BackBox closes the loop by automating remediation, ensuring that identified vulnerabilities are fixed with as little effort as possible. 

To address this FortiOS CVE, teams can reconfigure as a temporary fix or upgrade to the latest version as a more permanent solution. BackBox offers automations to handle either scenario. 

• If a customer chooses to mitigate through reconfiguration, BackBox provides the search and automations required to determine where a CVE is relevant and to identify the actions required to reconfigure. 
• If upgrading to the latest version is preferred, BackBox can help by quickly releasing an automation to do so.

Conclusion

No team wants to spend their holidays dealing with unwelcome surprises. Whenever events like this arise, BackBox makes it easy to verify whether you’re affected and act quickly to mitigate risk. 

What’s more, you can proactively manage the vulnerability lifecycle. By using IntelliChecks regularly, you can ensure you’re well configured or quickly implement configuration workarounds or updates to strengthen resilience. We’re also continuing to add features to make this even easier going forward.

Discover the advantages of BackBox today. Schedule a 30-minute demo for an interactive tour of the BackBox platform.