CVE-2025-14733: WatchGuard Firebox Out of Bounds Write Vulnerability

This vulnerability is an out-of-bounds write in the iked process of WatchGuard Fireware OS on Firebox appliances. It can allow a remote unauthenticated attacker to execute arbitrary code when the device processes IKEv2 traffic for certain VPN configurations. The issue matters because Firebox devices often sit at network perimeters and terminate both remote-access and site-to-site tunnels; successful exploitation can therefore grant an attacker a foothold inside the protected network without valid credentials.

How it works

CWE-787 describes a write operation that occurs outside the bounds of an allocated buffer. In this case the flaw resides in the iked process that handles Internet Key Exchange version 2 (IKEv2) messages. An attacker who can reach the IKEv2 listener may supply crafted packets that cause the process to write beyond the intended memory region, potentially altering control flow or data structures used by the VPN daemon.

The affected configurations are mobile-user VPN with IKEv2 and branch-office VPN using IKEv2 when the peer is defined as a dynamic gateway. No further exploit mechanics are documented in the available summary; defenders should consult the vendor advisory for precise packet or configuration details.

Am I affected? How to find it in your systems

WatchGuard Firebox appliances run Fireware OS and commonly terminate IKEv2 tunnels at the network edge. Inventory all Firebox devices that accept IKEv2 connections, whether for remote-access users or site-to-site links.

• Review device configuration for Mobile User VPN policies that enable IKEv2 and for Branch Office VPN tunnels configured with a dynamic gateway peer using IKEv2.
• Check the installed Fireware OS version against the ranges listed in the vendor advisory; the summary does not enumerate exact versions, so confirmation with the vendor is required.
• Examine firewall logs and IKE daemon telemetry for repeated or malformed IKEv2 negotiation attempts from unexpected source addresses; sustained anomalies may indicate reconnaissance or exploitation attempts.

How to remediate

Apply the vendor-supplied update that addresses the out-of-bounds write in the iked process. The CISA directive states to follow mitigations per vendor instructions or discontinue use if mitigations are unavailable.

After patching, review all IKEv2 policies to ensure they are still required and restrict the listener to the minimum necessary source addresses. Disable dynamic-gateway peers where static addresses can be used instead. Maintain current logging levels for the iked process to support future incident review.

If you can't patch immediately

Until the update can be applied, limit exposure by placing affected Firebox devices behind additional network segmentation so that only trusted networks can reach the IKEv2 UDP ports. Where a web-application firewall or virtual patching capability is available in front of the appliance, apply rules that drop malformed IKEv2 payloads before they reach the iked process.

Monitor for unexpected process restarts or memory-related error messages in the Firebox logs. If compensating controls cannot be implemented, follow the CISA guidance to discontinue use of the affected configuration or device.

If your data may have been exposed

An actively exploited out-of-bounds write that leads to remote code execution can result in unauthorized access and data exposure. Organizations that operate WatchGuard Firebox appliances should review authentication logs and VPN session records for signs of unexpected activity and run a free exposure scan of their domains to check known breach data.