CVE-2025-3719: Nozomi Networks CMC Auth Bypass Vulnerability

CVE-2025-3719 Overview

CVE-2025-3719 is a broken access control vulnerability ([CWE-863]) in the command-line interface (CLI) of Nozomi Networks CMC (Central Management Console) and Guardian appliances. The flaw allows an authenticated user with limited privileges to execute administrative CLI commands. Successful exploitation lets an attacker modify the device configuration or disrupt its availability, undermining the integrity of an operational technology (OT) monitoring deployment.

Critical Impact
An authenticated low-privileged user can issue administrative CLI commands on Nozomi CMC and Guardian appliances, altering configuration and affecting availability of OT network monitoring infrastructure.

Affected Products

Nozomi Networks CMC (Central Management Console)
Nozomi Networks Guardian
All versions prior to the vendor-supplied fix referenced in advisory NN-2025:5-01

Discovery Timeline

2025-10-07 - CVE-2025-3719 published to the National Vulnerability Database (NVD)
2025-10-09 - Last updated in NVD database
Vendor advisory - Nozomi Networks publishes Nozomi Networks Security Advisory NN-2025:5-01

Technical Details for CVE-2025-3719

Vulnerability Analysis

The vulnerability resides in the CLI authorization layer of Nozomi Networks CMC and Guardian products. The CLI does not consistently enforce role-based restrictions before executing privileged commands. As a result, an account scoped to limited privileges can invoke commands that should be reserved for administrators.

Nozomi Guardian provides OT and IoT network monitoring, while CMC aggregates data from multiple Guardian sensors. Both expose a management CLI used for configuration, diagnostics, and operational tasks. The missing authorization check allows a non-administrative authenticated user to reach administrative command handlers directly.

Because Guardian and CMC sit at the visibility layer of industrial networks, configuration tampering can disable monitoring, alter alerting rules, or take the appliance offline. This results in loss of telemetry from the OT environment during the attack window.

Root Cause

The root cause is improper authorization ([CWE-863]) in the CLI command dispatcher. A specific access restriction is not enforced for users with limited privileges, allowing privileged command paths to be reached without an administrative role check.

Attack Vector

Exploitation requires network access to the CLI and valid credentials for a low-privileged account. The attacker authenticates over the network, then issues administrative commands that the CLI fails to gate by role. No user interaction is required, and the attack complexity is low. Confidentiality is not directly affected, but integrity and availability of the device are at high risk.

No public proof-of-concept exploit, ExploitDB entry, or CISA KEV listing is associated with CVE-2025-3719 at the time of writing.

The vulnerability is described in prose only because no verified exploit code has been released. Refer to the Nozomi Networks Security Advisory for vendor-supplied technical detail.

Detection Methods for CVE-2025-3719

Indicators of Compromise

CLI sessions from non-administrative accounts that invoke configuration-changing commands such as user management, network configuration, or service control
Unexpected changes to Guardian or CMC configuration files, alerting rules, or sensor groupings
Service restarts, sensor disconnections, or monitoring gaps not correlated with scheduled maintenance
Authentication events for low-privileged accounts followed by privileged CLI command audit entries

Detection Strategies

Review CLI audit logs on CMC and Guardian appliances for commands executed by accounts that are not members of the administrator role
Baseline normal CLI command usage per account role and alert on deviations
Forward Nozomi appliance audit logs to a centralized SIEM or data lake for correlation with identity events
Ingested logs can be normalized via OCSF in the Singularity Data Lake to correlate low-privileged user sessions with privileged command execution across CMC and Guardian fleets

Monitoring Recommendations

Monitor for configuration drift on Guardian sensors and CMC, including changes to user accounts, network settings, and integration endpoints
Alert on availability changes such as sensor heartbeat loss, monitoring service restarts, or appliance reboots initiated through the CLI
Track authentication patterns for limited-privilege accounts, including off-hours logins and access from unusual source IPs

How to Mitigate CVE-2025-3719

Immediate Actions Required

Apply the fixed versions of Nozomi Networks CMC and Guardian as documented in advisory NN-2025:5-01
Audit all CMC and Guardian local accounts and remove or disable any non-essential low-privileged users
Restrict network access to the appliance CLI to a dedicated management network and trusted jump hosts
Review CLI audit logs since the appliance was deployed for evidence of unauthorized administrative commands

Patch Information

Nozomi Networks has published fixed releases for both CMC and Guardian. Refer to the Nozomi Networks Security Advisory NN-2025:5-01 for the specific fixed version numbers and upgrade procedures applicable to your deployment.

Workarounds

Limit CLI access to administrative accounts only by removing CLI login rights from any role that does not strictly require it
Enforce network-level access controls so that only authorized management hosts can reach the appliance SSH or CLI service
Require multi-factor authentication on the upstream jump host or identity provider used to reach the appliance CLI
Increase audit log retention and forward logs off-box to preserve evidence if the appliance is tampered with

bash

# Restrict CLI access to a management subnet (example host firewall rule)
# Replace 10.10.20.0/24 with your authorized management network
iptables -A INPUT -p tcp --dport 22 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j DROP