CVE-2026-3342 in Fireware OS
Summary
by MITRE • 03/03/2026
An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an authenticated privileged administrator to execute arbitrary code with root permissions via an exposed management interface.
This vulnerability affects Fireware OS 11.9 up to and including 11.12.4_Update1, 12.0 up to and including 12.11.7 and 2025.1 up to and including 2026.1.1.
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Analysis
by VulDB Data Team • 03/06/2026
The vulnerability identified as CVE-2026-3342 represents a critical out-of-bounds write flaw within WatchGuard Fireware OS that fundamentally undermines system security through a privilege escalation vector. This issue resides in the management interface component of the firewall operating system, creating a pathway for authenticated administrators to potentially gain root-level access and execute arbitrary code. The flaw specifically manifests when processing certain management interface requests, where improper input validation leads to memory corruption that can be exploited to overwrite adjacent memory locations with malicious data.
The technical implementation of this vulnerability stems from inadequate bounds checking within the Fireware OS management service, which operates with elevated privileges to handle administrative commands. When an authenticated administrator accesses the management interface, the system fails to properly validate the size and content of incoming data structures, allowing an attacker to craft malicious inputs that exceed allocated memory boundaries. This memory corruption directly enables code execution at the highest privilege level, effectively bypassing all standard security controls and access restrictions that normally protect the system from unauthorized modification. The vulnerability is particularly concerning because it leverages legitimate administrative access, making detection more difficult as the malicious activity appears to originate from authorized personnel.
The operational impact of CVE-2026-3342 extends far beyond simple privilege escalation, creating a comprehensive attack surface that can lead to complete system compromise. Once an attacker achieves root-level execution, they can manipulate firewall rules, modify system configurations, access all network traffic logs, and potentially use the compromised device as a pivot point for lateral movement within the network infrastructure. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under privilege escalation and persistence tactics, specifically targeting the execution and privilege escalation phases of an attack lifecycle. The affected versions span multiple major releases including Fireware OS 11.9 through 11.12.4_Update1, 12.0 through 12.11.7, and 2025.1 through 2026.1.1, indicating this flaw has persisted across significant software iterations and affects a broad user base of network security appliances.
Organizations must implement immediate mitigations including mandatory firmware updates to versions that address the memory validation issues, along with comprehensive monitoring of management interface access logs for anomalous patterns that might indicate exploitation attempts. Network segmentation strategies should be enhanced to limit direct access to management interfaces, while multi-factor authentication should be enforced for all administrative accounts. Security teams should also deploy intrusion detection systems specifically configured to identify malformed management interface requests that could indicate exploitation attempts. The vulnerability aligns with CWE-787, which describes out-of-bounds write conditions, and represents a significant concern for compliance with cybersecurity frameworks such as NIST SP 800-53 and ISO 27001, as it creates potential for unauthorized data access and system compromise that violates fundamental security principles of integrity and confidentiality.