CVE-2026-2417: Pharos Mosaic Controller Auth Bypass Flaw

CVE-2026-2417 Overview

A Missing Authentication for Critical Function vulnerability exists in Pharos Controls Mosaic Show Controller firmware version 2.15.3. This critical security flaw allows an unauthenticated attacker to bypass authentication mechanisms and execute arbitrary commands with root privileges on affected devices. The vulnerability is classified under CWE-306 (Missing Authentication for Critical Function), indicating that critical administrative functions are accessible without proper authentication verification.

Critical Impact

Unauthenticated remote attackers can execute arbitrary commands with root privileges, potentially gaining complete control over affected industrial control system devices.

Affected Products

• Pharos Controls Mosaic Show Controller firmware version 2.15.3

Discovery Timeline

• 2026-03-24 - CVE CVE-2026-2417 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-2417

Vulnerability Analysis

This vulnerability represents a fundamental authentication bypass in the Pharos Controls Mosaic Show Controller, an industrial control system (ICS) device used for show and lighting control applications. The flaw allows network-accessible attackers to invoke critical administrative functions without providing any authentication credentials. Once authentication is bypassed, attackers can execute arbitrary commands with root-level privileges, granting them complete control over the affected device.

The vulnerability is particularly concerning in ICS/SCADA environments where these controllers may manage critical infrastructure operations. Successful exploitation requires no user interaction and can be performed remotely over the network, making it highly attractive to threat actors targeting operational technology (OT) environments.

Root Cause

The root cause of CVE-2026-2417 is the absence of authentication checks on critical administrative functions within the Mosaic Show Controller firmware. The firmware fails to verify that requests to sensitive endpoints or functions originate from authenticated and authorized users. This design flaw allows any network-accessible attacker to directly invoke administrative capabilities that should be restricted to authenticated administrators only.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or user interaction. An attacker with network access to the vulnerable Mosaic Show Controller can:

1. Identify exposed administrative interfaces or functions that lack authentication requirements
2. Directly invoke critical functions without providing credentials
3. Execute arbitrary commands with root privileges on the underlying system
4. Potentially pivot to other connected devices within the ICS/OT network

The vulnerability can be exploited remotely by any attacker who can reach the device over the network. For detailed technical information, refer to the CISA ICS Advisory ICSA-26-083-01.

Detection Methods for CVE-2026-2417

Indicators of Compromise

• Unauthorized administrative commands or configuration changes on Mosaic Show Controller devices
• Unexpected network connections to management interfaces from untrusted IP addresses
• Log entries indicating command execution without corresponding authentication events
• Creation of unauthorized user accounts or modification of existing credentials
• Unusual process execution or system modifications on the controller device

Detection Strategies

• Monitor network traffic to Mosaic Show Controller devices for unauthenticated access attempts to administrative interfaces
• Implement intrusion detection rules to alert on command execution patterns targeting the controller
• Review device logs for administrative actions that lack corresponding authentication entries
• Deploy network segmentation monitoring to detect unauthorized access to ICS/OT network segments

Monitoring Recommendations

• Enable comprehensive logging on all Pharos Controls Mosaic Show Controller devices
• Implement network traffic analysis for devices in the ICS/OT environment
• Configure SIEM rules to correlate authentication events with administrative actions
• Establish baseline behavior profiles for controller devices to detect anomalous activity

How to Mitigate CVE-2026-2417

Immediate Actions Required

• Isolate affected Pharos Controls Mosaic Show Controller devices from untrusted networks immediately
• Implement network segmentation to restrict access to ICS/OT devices from corporate networks
• Deploy firewall rules to limit network access to the controller's management interfaces
• Review device logs for evidence of exploitation and unauthorized access

Patch Information

Organizations should consult the CISA ICS Advisory ICSA-26-083-01 for official patch information and vendor guidance. Contact Pharos Controls directly for firmware updates that address this vulnerability. Ensure all patches are tested in a staging environment before deployment to production ICS systems.

Workarounds

• Place affected devices behind a properly configured firewall that restricts access to authorized IP addresses only
• Implement VPN access for remote administration to prevent direct network exposure
• Disable unnecessary network services and interfaces on the controller
• Apply the principle of least privilege for all network access to ICS/OT environments
• Consider implementing additional authentication layers such as network access control (NAC) solutions

# Example firewall rule to restrict access to controller management interface
# Allow only trusted management workstations to access the device
iptables -A INPUT -s 192.168.100.0/24 -d <controller_ip> -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -s 192.168.100.0/24 -d <controller_ip> -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -d <controller_ip> -p tcp --dport 80 -j DROP
iptables -A INPUT -d <controller_ip> -p tcp --dport 443 -j DROP