Fortinet Warns of New Post-Exploitation Threats: What You Need to Know

TL;DR

Fortinet has issued an advisory highlighting a new post-exploitation technique targeting known vulnerabilities in FortiOS and FortiGate products. This threat allows read-only access to device files, potentially exposing configurations. Administrators are urged to upgrade to the latest FortiOS versions, review device configurations, reset exposed credentials, and consider disabling SSL-VPN as a temporary mitigation.

Introduction

Fortinet has recently released an advisory detailing a new post-exploitation technique that leverages previously known vulnerabilities in FortiOS and FortiGate products. This technique enables threat actors to create a malicious file, granting them read-only access to files on the devices’ file systems. This access can include sensitive configurations, posing a significant security risk.

Detailed Analysis

Threat Overview

The new post-exploitation technique identified by Fortinet involves the creation of a malicious file that exploits known vulnerabilities in FortiOS and FortiGate products. This file allows threat actors to gain read-only access to the devices’ file systems, potentially exposing critical configurations and other sensitive information.

Impact and Mitigation

To address this threat, Fortinet recommends several mitigation steps:

1. Upgrade FortiOS: Administrators should upgrade to the following FortiOS versions to remove the malicious file and prevent re-compromise:
   • FortiOS 7.6.2
   • FortiOS 7.4.7
   • FortiOS 7.2.11
   • FortiOS 7.0.17
   • FortiOS 6.4.16

2. Review Configurations: Thoroughly review the configurations of all in-scope devices to ensure no unauthorized changes have been made.

3. Reset Credentials: Reset any credentials that may have been exposed due to this vulnerability.

4. Disable SSL-VPN: As a temporary mitigation until the patch is applied, consider disabling SSL-VPN functionality, as the exploitation of the file requires SSL-VPN to be enabled.

Additional Resources

For more detailed information and mitigation strategies, refer to the following resources:

• [Analysis of Threat Actor Activity

  Fortinet Blog](https://www.fortinet.com/blog/psirt-blogs/analysis-of-threat-actor-activity)

• [Recommended Steps to Execute

  Fortinet Community](https://community.fortinet.com/t5/FortiGate/Technical-Tip-Recommended-steps-to-execute-in-case-of-a/ta-p/230694)

Organizations are encouraged to report any incidents or anomalous activity to CISA’s 24/7 Operations Center at [email protected] or (888) 282-0870.

For more details, visit the full article: CISA Alert

Conclusion

The new post-exploitation technique highlighted by Fortinet underscores the importance of staying vigilant and proactive in cybersecurity practices. By following the recommended mitigation steps and staying informed about the latest threats, organizations can better protect their systems and data from potential breaches.

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For further insights, check:

• CISA Alerts
• Fortinet Blog