CVE-2026-66149 in Email Security
Summary
by MITRE • 08/11/2026
Improper Control of Generation of Code ('Code Injection') Vulnerability in the SonicWall Email Security appliance allows an authenticated attacker with access to the SonicWall Email Security restricted CLI can inject arbitrary OS commands that execute as root via netmask.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical code injection flaw in SonicWall Email Security appliances that falls under the CWE-94 category of Improper Control of Generation of Code. The vulnerability specifically manifests when an authenticated attacker gains access to the restricted command line interface and leverages a weakness in how network mask parameters are processed. The flaw allows malicious input to be interpreted as executable commands rather than simple configuration data, creating a pathway for arbitrary code execution with root privileges.
The technical exploitation occurs through the netmask parameter handling within the appliance's command processing system. When an attacker submits crafted input containing special characters or command sequences through this interface, the system fails to properly sanitize or validate the input before using it in system calls. This failure creates a direct injection vector where malicious commands can be executed with the highest available privileges, effectively granting complete system control. The restricted CLI access requirement means that attackers must first compromise authentication credentials or gain physical access to the appliance, but once achieved, the impact is devastating.
The operational implications of this vulnerability are severe for organizations relying on SonicWall Email Security appliances. Attackers who successfully exploit this flaw can gain unrestricted access to email server functionality, potentially compromising email communications, exfiltrating sensitive data, modifying email routing, or even using the appliance as a pivot point to attack internal network resources. The root privilege escalation means that attackers can modify system files, install backdoors, disable security features, or completely compromise the integrity of the email infrastructure. This vulnerability directly aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation.
Organizations should implement immediate mitigations including restricting access to the restricted CLI interface, implementing strict input validation controls, and monitoring for anomalous command execution patterns. Network segmentation and principle of least privilege should be enforced to limit potential lateral movement if an attacker gains access. Regular security updates from SonicWall should be deployed immediately, and system administrators should conduct thorough access reviews to ensure only authorized personnel have CLI privileges. The vulnerability underscores the importance of input validation and proper sanitization practices in network security appliances, as highlighted by CWE-170 and related security standards that emphasize the need for robust parsing and validation of all user-supplied data before system processing occurs.