CVE-2026-21410: InSAT MasterSCADA BUK-TS SQLi Vuln

CVE-2026-21410 Overview

CVE-2026-21410 is a critical SQL Injection vulnerability affecting InSAT MasterSCADA BUK-TS, a SCADA (Supervisory Control and Data Acquisition) system used in industrial control environments. The vulnerability exists in the main web interface, where improper input validation allows attackers to inject malicious SQL queries. Successful exploitation of this vulnerability could enable remote code execution on the affected system, potentially compromising critical industrial infrastructure.

Critical Impact

This SQL Injection vulnerability in industrial control system software could allow unauthenticated remote attackers to execute arbitrary code on systems controlling critical infrastructure, potentially leading to operational disruption, data theft, or physical damage to controlled processes.

Affected Products

• InSAT MasterSCADA BUK-TS (all versions prior to patched release)
• Industrial control systems utilizing MasterSCADA BUK-TS web interface
• SCADA deployments with network-accessible web interfaces

Discovery Timeline

• 2026-02-24 - CVE CVE-2026-21410 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-21410

Vulnerability Analysis

This vulnerability is classified as CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), commonly known as SQL Injection. The flaw resides in the main web interface of InSAT MasterSCADA BUK-TS, where user-supplied input is not properly sanitized before being incorporated into SQL queries executed by the backend database.

The network-accessible attack vector means that any attacker with network access to the vulnerable web interface can attempt exploitation without requiring authentication or user interaction. This is particularly concerning in operational technology (OT) environments where SCADA systems may control critical infrastructure processes.

Root Cause

The root cause of this vulnerability is improper input validation and sanitization in the web interface's database query construction. The application fails to adequately neutralize special characters and SQL metacharacters in user-supplied input before constructing SQL queries. This allows attackers to manipulate the intended query logic and inject arbitrary SQL commands that the database server will execute with the application's privileges.

Attack Vector

The attack is network-based and requires no authentication or special privileges. An attacker can craft malicious HTTP requests to the vulnerable endpoint containing SQL injection payloads. When the web interface processes these requests, the malicious SQL code is executed against the backend database. Depending on the database configuration and application privileges, this could allow attackers to:

• Extract sensitive data from the database
• Modify or delete database records
• Execute operating system commands through database-specific functions
• Potentially achieve full remote code execution on the underlying server

The vulnerability is particularly dangerous in ICS/SCADA environments where successful exploitation could impact physical processes and industrial operations controlled by the system. For detailed technical information, refer to the CISA ICS Advisory ICSA-26-055-01.

Detection Methods for CVE-2026-21410

Indicators of Compromise

• Unusual SQL error messages in web server logs indicating injection attempts
• Unexpected database queries containing SQL metacharacters such as single quotes, UNION, SELECT, or -- comment sequences
• Anomalous outbound connections from the SCADA server to unknown external addresses
• Evidence of unauthorized data extraction or database modifications
• Web access logs showing requests with encoded SQL injection payloads to the vulnerable endpoint

Detection Strategies

• Deploy web application firewalls (WAF) with SQL injection detection rules to monitor and block malicious requests
• Implement database activity monitoring to detect unusual query patterns or unauthorized access attempts
• Configure intrusion detection systems (IDS) with signatures for common SQL injection attack patterns
• Enable detailed logging on the web interface and correlate with database audit logs to identify exploitation attempts

Monitoring Recommendations

• Monitor network traffic to and from SCADA web interfaces for suspicious patterns or known attack signatures
• Implement real-time alerting for SQL error messages that may indicate injection attempts
• Establish baseline normal database activity and alert on deviations that could indicate compromise
• Regularly review authentication logs for any signs of unauthorized access following potential exploitation

How to Mitigate CVE-2026-21410

Immediate Actions Required

• Isolate affected MasterSCADA BUK-TS systems from untrusted networks immediately
• Restrict web interface access to only authorized IP addresses using firewall rules
• Disable remote access to the web interface if not operationally required
• Implement network segmentation to limit exposure of ICS/SCADA assets
• Deploy web application firewall rules to block SQL injection attempts

Patch Information

Organizations should consult the CISA ICS Advisory ICSA-26-055-01 for the latest vendor patch information and remediation guidance. Contact InSAT directly for specific patch availability and upgrade instructions for MasterSCADA BUK-TS deployments. Additional technical details are available in the GitHub CSAF File.

Workarounds

• Place the vulnerable web interface behind a reverse proxy with SQL injection filtering capabilities
• Implement strict input validation at the network perimeter using application-layer firewalls
• Use VPN or other secure access mechanisms to limit exposure of the web interface to trusted users only
• Disable unnecessary web interface features until a patch is available
• Consider temporarily disabling the web interface entirely if operational requirements permit

# Network isolation example - restrict web interface access
# Add firewall rules to limit access to trusted management IPs only
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP