Early this February, Fortinet released an advisory for an "out-of-bounds write vulnerability" that could lead to remote code execution. The issue affected the SSL VPN component of their FortiGate network appliance and was potentially already being exploited in the wild. In this post we detail the steps we took to identify the patched vulnerability and produce a working exploit.
On January 10, 2024, Volexity publicly shared details of targeted attacks by UTA00178 exploiting two zero-day vulnerabilities (CVE-2024-21887 and CVE-2023-46805) in Ivanti Connect Secure (ICS) VPN appliances. On the same day, Ivanti published a mitigation that could be applied to ICS VPN appliances to prevent exploitation of these vulnerabilities. Since publication of these details, Volexity has continued to monitor its existing customers for exploitation. Volexity has also been contacted by multiple organizations that saw signs of compromise by way of mismatched file detections. Volexity has been actively working multiple new cases of organizations with compromised ICS VPN appliances.
Over the Memorial Day weekend in the United States, Volexity conducted an incident response investigation involving two Internet-facing web servers belonging to one of its customers that were running Atlassian Confluence Server software. The investigation began after suspicious activity was detected on the hosts, which included JSP webshells being written to disk