A critical vulnerability (CVSS4.0 9.3) in WatchGuard Fireware OS has been identified that could allow a threat actor to remotely execute arbitrary code.
The bug, tracked as CVE-2025-9242, is an out-of-bounds write vulnerability affecting mobile user VPN with IKEv2 and the branch office VPN (BOVPN) using IKEv2 when configured with a dynamic gateway peer.
The WatchGuard advisory noted that if the Firebox security platform was previously configured with the above VPN and IKEv2 gateway peers it could still be vulnerable.
The vulnerability affects Fireware OS 11.10.2 up to and including 11.12.4_Update1, 12.0 up to and including 12.11.3 and 2025.1.
WatchGuard’s Firebox is a next-generation firewall (NGFW) that acts as a security gateway, controlling traffic between external and trusted networks, and includes advanced features like intrusion prevention, anti-spam and content filtering.
It can be deployed as a physical appliance, in the cloud or as a virtual machine.
The Shadowserver foundation noted that based on IP data scans, there could be over 71,000 vulnerable devices as of October 17.
Details on the vulnerability are now available on the US National Vulnerability Database (NVD) and WatchGuard has also published a security advisory.
If the Firebox is only configured with Branch Office VPN tunnels to static gateway peers and the owner is not able to immediately upgrade the device to a version of Fireware OS with the vulnerability resolution, WatchGuard has provided recommendations for a temporary workaround.
In its advisory, WatchGuard noted that it recommends BOVPN secure access policies are configured with a narrower scope to handle incoming VPN traffic, due to increasing attacks against exposed VPNs that target a wide range of vendors.
