CVE-2026-25086: WebCTRL Auth Bypass Vulnerability

CVE-2026-25086 Overview

CVE-2026-25086 is a port binding vulnerability affecting Automated Logic WebCTRL building automation systems. Under certain conditions, an attacker with local access could bind to the same port used by WebCTRL, enabling them to craft and send malicious packets while impersonating the legitimate WebCTRL service. This attack does not require code injection into the WebCTRL software itself, making it particularly concerning for industrial control system (ICS) environments.

Critical Impact

Successful exploitation allows attackers to impersonate the WebCTRL service, potentially intercepting sensitive building automation data, sending malicious commands to HVAC and other building systems, or disrupting critical building management operations.

Affected Products

• Automated Logic WebCTRL (specific versions not disclosed in advisory)
• Building automation systems utilizing WebCTRL services
• ICS/SCADA environments with WebCTRL deployments

Discovery Timeline

• 2026-03-21 - CVE-2026-25086 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2026-25086

Vulnerability Analysis

This vulnerability is classified under CWE-605 (Multiple Binds to the Same Port), which occurs when an application allows multiple processes or threads to bind to the same network port simultaneously. In the context of WebCTRL, this architectural weakness enables a local attacker to establish a competing service on the same port used by the legitimate WebCTRL application.

The local attack vector indicates that an attacker must already have some level of access to the host system running WebCTRL. Once positioned, the attacker can exploit the port binding weakness to intercept communications intended for the legitimate service or inject malicious responses. This type of attack is particularly dangerous in building automation contexts where compromised commands could affect physical systems including HVAC, lighting, and access control.

Root Cause

The root cause of CVE-2026-25086 lies in improper socket binding configuration within the WebCTRL service. When a service does not use exclusive binding options (such as SO_REUSEADDR misconfiguration or missing SO_EXCLUSIVEADDRUSE on Windows systems), the operating system may allow multiple processes to bind to the same port. This creates a race condition where the attacker's malicious service can receive connections or packets intended for the legitimate WebCTRL service.

Building automation systems like WebCTRL often run on Windows-based platforms where proper exclusive socket binding requires explicit configuration. The absence of these protections allows the service impersonation attack described in this vulnerability.

Attack Vector

The attack requires local access to the system running WebCTRL. An attacker would:

1. Gain local access to the WebCTRL host system through legitimate credentials, malware, or physical access
2. Identify the port(s) used by the WebCTRL service
3. Create a malicious service that binds to the same port
4. Intercept incoming connections or craft malicious responses to impersonate the legitimate WebCTRL service
5. Potentially send unauthorized commands to building automation equipment or harvest sensitive operational data

The vulnerability does not require any user interaction and can be exploited with no privileges, though confidentiality and integrity impacts are rated as high. Availability is not directly affected, which may allow the attack to persist undetected while the legitimate service continues partial operation.

Detection Methods for CVE-2026-25086

Indicators of Compromise

• Multiple processes bound to WebCTRL service ports (typically TCP ports used by the web interface and control protocols)
• Unexpected network services running on the WebCTRL host system
• Anomalous traffic patterns or responses from WebCTRL services
• Unusual process creation events on WebCTRL servers

Detection Strategies

• Monitor for duplicate socket bindings on critical service ports using tools like netstat or ss with process identification
• Implement application whitelisting to detect unauthorized executables attempting to bind to WebCTRL ports
• Deploy endpoint detection and response (EDR) solutions to identify suspicious process behavior on ICS hosts
• Enable Windows Security Event logging for socket operations and service creation events

Monitoring Recommendations

• Establish baseline network behavior for WebCTRL communications and alert on deviations
• Configure SentinelOne Singularity Platform to monitor for unauthorized process bindings on critical OT systems
• Implement network segmentation monitoring to detect lateral movement toward WebCTRL hosts
• Review ICS-specific monitoring guidance from CISA ICS Advisory #ICSA-26-078-08

How to Mitigate CVE-2026-25086

Immediate Actions Required

• Review the CISA ICS Advisory #ICSA-26-078-08 for vendor-specific guidance and patches
• Audit local access to all systems running WebCTRL and restrict unnecessary accounts
• Implement network segmentation to isolate WebCTRL systems from general corporate networks
• Deploy host-based monitoring on WebCTRL servers to detect unauthorized socket bindings
• Contact Automated Logic support for specific patch or configuration guidance per their Security Commitment

Patch Information

Patch details have not been disclosed in the public CVE data. Organizations should consult the CISA ICS Advisory #ICSA-26-078-08 and Automated Logic directly for specific remediation steps. The GitHub CSAF Document may contain additional structured vulnerability information including affected version ranges and recommended updates.

Workarounds

• Implement strict access controls limiting which users and processes can bind to network ports on WebCTRL systems
• Deploy application whitelisting to prevent unauthorized executables from running on WebCTRL hosts
• Use host-based firewalls to restrict inbound connections to WebCTRL ports from trusted sources only
• Enable audit logging for socket operations and monitor for duplicate bindings
• Consider running WebCTRL services under dedicated service accounts with minimal privileges

# Windows: Check for multiple processes bound to a specific port
netstat -ano | findstr :<PORT_NUMBER>

# Linux: Identify processes sharing port bindings
ss -tlnp | grep :<PORT_NUMBER>

# Verify exclusive binding configuration in Windows firewall
netsh advfirewall firewall show rule name=all | findstr /i "webctrl"