CVE-2025-3394 Overview
CVE-2025-3394 is an Incorrect Permission Assignment for Critical Resource vulnerability [CWE-732] affecting ABB Automation Builder through version 2.8.0. The flaw permits a local, low-privileged user to interact with critical resources whose permissions are set too broadly. Successful exploitation impacts confidentiality, integrity, and availability of the engineering workstation. ABB Automation Builder is widely deployed to configure PLCs, safety controllers, and drives in industrial environments, making the engineering host a high-value target for lateral movement into operational technology (OT) networks.
Critical Impact
A local authenticated attacker can leverage permissive access controls on Automation Builder resources to escalate privileges and tamper with PLC engineering artifacts.
Affected Products
- ABB Automation Builder versions through 2.8.0
- Engineering workstations running vulnerable Automation Builder installations
- Downstream ABB PLCs and safety controllers configured through affected hosts
Discovery Timeline
- 2025-04-30 - CVE-2025-3394 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in the NVD database
Technical Details for CVE-2025-3394
Vulnerability Analysis
CVE-2025-3394 is rooted in Incorrect Permission Assignment for Critical Resource [CWE-732]. Automation Builder installs or manages resources — such as configuration files, service objects, or executables — with permissions that grant broader access than required. A local user without administrative rights can read, modify, or replace these resources. Because Automation Builder is the primary engineering tool for ABB controllers, tampering with its resources allows an attacker to alter PLC programs, inject malicious logic during downloads, or harvest project credentials. The attack requires local access and low privileges but no user interaction, making it viable against shared engineering workstations and jump hosts common in industrial control system (ICS) environments.
Root Cause
The root cause is an over-permissive access control list (ACL) or file mode assigned to installation directories, service configurations, or runtime artifacts belonging to Automation Builder. Standard operating system enforcement cannot mitigate the issue because the application itself provisions these resources with weak permissions during installation or normal operation.
Attack Vector
An authenticated local attacker on a host running Automation Builder targets the writable critical resource. The attacker replaces or modifies the resource so that a higher-privileged process, service, or engineer subsequently loads attacker-controlled content. This yields privilege escalation on the workstation and can pivot into modifications of controller projects pushed to field devices.
No verified proof-of-concept code is publicly available. See the ABB security advisory for vendor technical details.
Detection Methods for CVE-2025-3394
Indicators of Compromise
- Unexpected modification timestamps on Automation Builder installation directories, DLLs, or configuration files
- New or altered files owned by non-administrative users within Automation Builder program paths
- Automation Builder services or processes loading modules from user-writable locations
Detection Strategies
- Baseline file permissions on Automation Builder directories and alert on ACL changes granting write access to non-privileged principals
- Monitor for local privilege escalation patterns originating from Automation Builder child processes
- Correlate engineering workstation logins with subsequent modifications to PLC project files and controller downloads
Monitoring Recommendations
- Enable Windows object access auditing on Automation Builder installation paths and configuration stores
- Forward endpoint telemetry from ICS engineering workstations to a centralized data lake for retention and hunting
- Alert on any writes to Automation Builder binaries by accounts other than SYSTEM or approved administrators
How to Mitigate CVE-2025-3394
Immediate Actions Required
- Restrict interactive and remote access to Automation Builder engineering workstations to authorized engineers only
- Manually harden ACLs on Automation Builder installation directories to remove write permissions for standard users
- Inventory all hosts running Automation Builder 2.8.0 or earlier and prioritize them for remediation
Patch Information
ABB has published guidance in advisory 3ADR011407. Refer to the ABB Automation Builder security advisory for fixed versions, workarounds, and vendor-recommended configuration changes. Upgrade to the version identified by ABB as remediated and validate that post-upgrade file permissions match the vendor baseline.
Workarounds
- Enforce least privilege on engineering hosts and block standard users from logging into workstations that run Automation Builder
- Segment engineering workstations into a dedicated OT management VLAN with strict jump-host access controls
- Apply application allowlisting to prevent execution of unauthorized binaries from Automation Builder directories
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
