CVE-2025-26689: CHOCO TEI WATCHER mini Auth Bypass Flaw

CVE-2025-26689 Overview

A Direct Request vulnerability, commonly known as "Forced Browsing" (CWE-425), exists in the CHOCO TEI WATCHER mini (IB-MCT001) industrial camera device across all versions. This vulnerability allows remote attackers to bypass authentication mechanisms by sending specially crafted HTTP requests directly to restricted resources. Successful exploitation enables unauthorized access to sensitive product data, deletion of stored information, and modification of device settings without proper authorization.

The CHOCO TEI WATCHER mini is an industrial monitoring camera used in production line environments for quality control and stoppage recording. The vulnerability's presence in an ICS/OT environment makes it particularly concerning, as compromised industrial cameras could lead to surveillance of manufacturing processes, disruption of quality control systems, or serve as an entry point for broader network compromise.

Critical Impact

Remote unauthenticated attackers can obtain, delete, or modify product data and settings on CHOCO TEI WATCHER mini industrial cameras, potentially compromising production line monitoring and quality control systems.

Affected Products

• CHOCO TEI WATCHER mini (IB-MCT001) - All versions

Discovery Timeline

• 2025-03-31 - CVE-2025-26689 published to NVD
• 2025-04-01 - Last updated in NVD database

Technical Details for CVE-2025-26689

Vulnerability Analysis

The vulnerability stems from improper access control implementation in the web interface of the CHOCO TEI WATCHER mini device. The application fails to properly verify that users are authorized before processing requests to sensitive endpoints. This Forced Browsing weakness allows attackers to directly access restricted URLs or resources that should require authentication, bypassing the intended access control mechanisms entirely.

Industrial control system (ICS) devices like this production line camera often have limited security controls due to their embedded nature and operational requirements. The lack of proper authorization checks means that any network-accessible attacker can interact with protected functionality simply by knowing or guessing the correct URL paths.

Root Cause

The root cause is a missing authorization check (CWE-425: Direct Request) in the device's HTTP request handling logic. When the web server receives requests for protected resources, it fails to validate whether the requesting user has been properly authenticated and authorized. This architectural flaw allows direct access to administrative functions, data retrieval endpoints, and configuration interfaces without credential verification.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker with network access to the vulnerable device can craft HTTP requests targeting known or enumerated endpoints. The attack methodology typically involves:

1. Network reconnaissance to identify CHOCO TEI WATCHER mini devices
2. Enumeration of accessible URL paths and endpoints
3. Direct HTTP requests to sensitive resources bypassing authentication
4. Data exfiltration, deletion, or configuration manipulation

Since the vulnerability affects the HTTP interface directly, attackers can leverage standard web penetration testing tools to discover and exploit unprotected endpoints. The network attack vector combined with no authentication requirements makes this vulnerability trivial to exploit once a target device is identified.

Detection Methods for CVE-2025-26689

Indicators of Compromise

• Unexpected HTTP requests to administrative or configuration endpoints on CHOCO TEI WATCHER mini devices
• Unauthorized access patterns in device logs showing direct requests to protected resources without prior authentication
• Configuration changes or data deletions without corresponding legitimate administrator activity
• Network traffic to ICS camera devices from unexpected source IP addresses

Detection Strategies

• Implement network monitoring to detect unusual HTTP traffic patterns to ICS camera devices
• Deploy ICS-aware intrusion detection systems (IDS) to identify forced browsing attack signatures
• Enable and monitor access logs on network infrastructure between IT and OT segments
• Use network segmentation monitoring to detect lateral movement attempts toward ICS devices

Monitoring Recommendations

• Establish baselines for normal HTTP communication patterns with CHOCO TEI WATCHER mini devices
• Configure alerts for configuration changes or data access outside of maintenance windows
• Monitor for enumeration activity such as sequential URL path probing against device endpoints
• Implement anomaly detection for authentication bypass attempts on ICS network segments

How to Mitigate CVE-2025-26689

Immediate Actions Required

• Isolate affected CHOCO TEI WATCHER mini devices from direct internet access
• Implement network segmentation to restrict access to only authorized management systems
• Deploy firewall rules to limit HTTP access to the device from trusted IP addresses only
• Review device logs for signs of prior exploitation or unauthorized access

Patch Information

According to the CISA ICS Advisory ICSA-25-084-04, this vulnerability currently has no patch available from the vendor. Organizations should implement compensating controls as outlined in the vendor advisory and CISA recommendations. Additional details are available in the Inaba ChocoMini Vulnerability PDF and JVN Vulnerability Report.

Workarounds

• Place all affected devices behind a properly configured firewall that restricts network access
• Implement VPN or jump server requirements for any remote access to the device network segment
• Use application-layer gateways or reverse proxies with authentication to control access to device interfaces
• Consider physical isolation of production line cameras from general network infrastructure until patches are available

# Example firewall rule to restrict access to CHOCO TEI WATCHER mini devices
# Allow only authorized management hosts (replace with actual management IP)
iptables -A FORWARD -d <CAMERA_IP> -p tcp --dport 80 -s <MANAGEMENT_HOST_IP> -j ACCEPT
iptables -A FORWARD -d <CAMERA_IP> -p tcp --dport 80 -j DROP

# For network segmentation, ensure ICS devices are on isolated VLAN
# and only allow traffic from authorized jump hosts