CVE-2026-33390 Overview
CVE-2026-33390 is an Incorrect Privilege Assignment vulnerability [CWE-266] affecting the synchronization functionality of Nozomi Networks Arc sensors. Arc sensors improperly receive command-line interface (CLI) permissions during the sync process. An authenticated user with limited privileges can push administrative CLI commands through the synchronization channel. Successful exploitation lets the attacker alter device configuration or degrade device availability.
Critical Impact
An authenticated low-privileged user can escalate to administrative CLI capabilities on Arc sensors, modifying configuration and impacting availability of monitored operational technology assets.
Affected Products
- Nozomi Networks Arc sensors (see the Nozomi Networks Security Advisory NN-2026:13-01 for version specifics)
- Deployments relying on the sensor synchronization functionality
- Environments with multiple authenticated CLI users of differing privilege tiers
Discovery Timeline
- 2026-07-09 - CVE-2026-33390 published to the National Vulnerability Database
- 2026-07-09 - Last updated in NVD database
Technical Details for CVE-2026-33390
Vulnerability Analysis
The flaw resides in how the platform propagates permissions when Arc sensors synchronize with the central management component. During sync, Arc sensors are assigned CLI permissions that exceed the privilege level intended for the requesting user. This breaks the separation between administrative CLI operations and lower-tier user roles.
An authenticated user with limited privileges can issue administrative CLI commands routed through the sync channel. Because the sync layer accepts and executes those commands with elevated CLI rights, the platform trusts operations that should have been rejected. The result is a horizontal-to-vertical privilege escalation confined to sensor-level configuration and availability.
Root Cause
The root cause is improper privilege assignment [CWE-266] in the synchronization path. Permission checks tied to the authenticated user identity are not enforced at the CLI dispatch stage inside the sync flow. The sync process treats sensor-side CLI actions as authorized regardless of the originating user's role.
Attack Vector
Exploitation requires network access and valid credentials with limited privileges. No user interaction is required. The attacker authenticates to the management interface, then crafts CLI operations that traverse the Arc sensor sync channel. The platform executes those operations with administrative CLI rights, resulting in configuration tampering or denial of service on the sensor. Refer to the Nozomi Networks Security Advisory for protocol-level details.
Detection Methods for CVE-2026-33390
Indicators of Compromise
- Administrative CLI commands originating from user accounts that lack the corresponding role assignment
- Unexpected configuration changes on Arc sensors correlated with recent sync events
- Sensor availability drops, restarts, or service interruptions immediately following authenticated sessions from low-privileged users
- Sync operations containing CLI payloads that fall outside routine synchronization traffic patterns
Detection Strategies
- Correlate authentication logs for low-privileged accounts with sensor configuration change events during the same session window
- Audit CLI command execution records on Arc sensors for actions that do not map to an administrator identity
- Alert on privilege boundary violations where a user role differs from the effective permission of a completed CLI action
Monitoring Recommendations
- Ingest management console and Arc sensor logs into a centralized platform and normalize identity, role, and command fields
- Baseline routine sync traffic volume and content, then flag deviations that include administrative directives
- Monitor sensor uptime and configuration drift as continuous availability signals
How to Mitigate CVE-2026-33390
Immediate Actions Required
- Apply the fixed release referenced in the Nozomi Networks Security Advisory NN-2026:13-01
- Review all Arc sensor user accounts and remove or downgrade accounts that do not require access
- Rotate credentials for any low-privileged accounts that may have been used to interact with the sync functionality
- Audit recent sensor configuration changes and restore known-good configurations where tampering is suspected
Patch Information
Nozomi Networks has published fix guidance in advisory NN-2026:13-01. Administrators should upgrade affected Arc sensor and management components to the versions listed in the vendor advisory. Consult the Nozomi Networks Security Advisory for exact fixed versions and upgrade procedures.
Workarounds
- Restrict network reachability of the management interface to trusted administrative networks and jump hosts
- Enforce least privilege by removing CLI-adjacent capabilities from any user role that does not require administrative access
- Enable multi-factor authentication on all accounts with access to the management console
- Increase logging verbosity on sensor sync and CLI subsystems to accelerate identification of anomalous activity
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
