CVE-2026-19317 in Fireware OS
Summary
by MITRE • 08/28/2026
An out-of-bounds read vulnerability in the WatchGuard Fireware OS iked process allows a remote unauthenticated attacker to create a Denial of Service (DoS) condition in VPN processing by sending specially crafted network traffic.
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Analysis
by VulDB Data Team • 08/28/2026
The identified vulnerability resides within the Internet Key Exchange daemon, commonly referred to as iked, which is a critical component of the WatchGuard Fireware operating system responsible for managing IPsec security associations and key exchange protocols. This specific flaw manifests as an out-of-bounds read condition, indicating that the application attempts to access memory locations beyond the allocated buffer boundaries during the processing of incoming network packets. The root cause typically stems from insufficient validation of input data lengths or indices before performing memory copy operations or array accesses within the IKE protocol handler. Because this process operates at a low level in the networking stack and handles sensitive cryptographic negotiations, any deviation in expected packet structure can lead to immediate instability in the service execution flow.
From an operational perspective, this vulnerability allows for remote exploitation by unauthenticated attackers who do not require valid credentials or prior network access to initiate the attack vector. By transmitting specially crafted packets that trigger the erroneous memory read condition, an attacker can cause the iked process to crash or become unresponsive. This results in a Denial of Service condition specifically targeting VPN connectivity and management functions on the affected firewall appliance. Since IKE is fundamental to establishing secure tunnels for remote access and site-to-site connections, disrupting this service effectively severs all active IPsec sessions and prevents new ones from being established, thereby compromising the availability of protected network resources that rely on encrypted communication channels.
The security implications extend beyond simple service disruption, as repeated exploitation attempts may lead to information leakage depending on how the operating system handles memory faults in user-space daemons. If the out-of-bounds read accesses sensitive data structures such as session keys or configuration parameters before crashing, it could potentially expose cryptographic material to an attacker who can monitor network traffic for side-channel effects or subsequent error messages that reveal internal state details. This aligns with CWE-125, which describes Out-of-Bounds Read vulnerabilities where software reads memory past the end of a buffer, and also relates to CWE-400 regarding Uncontrolled Resource Consumption if the crash leads to resource leaks or repeated restart cycles exhausting system resources.
In terms of threat modeling, this vulnerability maps directly to MITRE ATT&CK technique T1498, Network Denial of Service, specifically under the sub-category of Direct Network Floods or Protocol Abuse. The attacker leverages protocol-specific logic flaws rather than brute-force volume attacks to achieve service disruption with minimal network footprint. This makes detection through standard volumetric intrusion prevention systems more challenging, as the malicious packets may appear structurally valid until processed by the vulnerable IKE parser.
Mitigation strategies primarily involve applying vendor-provided software updates that patch the memory handling routines within the iked binary. Administrators should ensure their WatchGuard Fireware OS is updated to a version where this specific out-of-bounds read condition has been resolved through improved input validation and bounds checking mechanisms. In environments where immediate patching is not feasible, implementing strict network access controls to restrict IKE traffic sources can reduce exposure. Additionally, enabling logging for VPN connection attempts allows security teams to monitor for patterns indicative of exploitation attempts, such as a high volume of failed or malformed IKE negotiation requests from single source addresses, facilitating rapid incident response and isolation of affected segments until the vulnerability is remediated.