Automation Studio Insufficient Server Certificate Validation
Plan Patch7.4SA25P004Jan 19, 2026
Attack VectorNetwork
Auth RequiredNone
ComplexityHigh
User InteractionNone needed
Summary
Insufficient server certificate validation in Automation Studio versions prior to 6.5 allows an attacker positioned on the network to perform a man-in-the-middle attack. When Automation Studio connects to a server using ANSL over TLS or OPC-UA protocol, the server's certificate is not properly validated, allowing an attacker to masquerade as a trusted server and potentially intercept or modify communications.
What this means
What could happen
An attacker on the network could impersonate a trusted server when Automation Studio connects using ANSL over TLS or OPC-UA, potentially deceiving operators into accepting malicious data or commands that could alter process setpoints or operations.
Who's at risk
Software developers and control engineers using B&R Automation Studio (formerly ABB Automation Studio) for programming PLCs, motion controllers, and distributed control systems in manufacturing, water utilities, and power generation facilities.
How it could be exploited
An attacker performs a man-in-the-middle attack on the network between an Automation Studio workstation and a server. When Automation Studio attempts to establish a TLS connection via ANSL or OPC-UA protocol, the attacker's server certificate is accepted without proper validation, allowing the attacker to intercept and modify communications.
Prerequisites
- Network access to ANSL over TLS or OPC-UA traffic between Automation Studio and target server
- Ability to perform man-in-the-middle attack (ARP spoofing, DNS spoofing, or network position)
- Automation Studio version prior to 6.5
Remotely exploitableNo authentication required for man-in-the-middle positionMan-in-the-middle attack complexityAffects engineering tools that program safety-critical controllers
Exploitability
Low exploit probability (EPSS 0.0%)
Affected products (1)
ProductAffected VersionsFix Status
Automation Studio <6.5<6.56.5
Remediation & Mitigation
0/3
Schedule — requires maintenance window
0/1Patching may require device reboot — plan for process interruption
HOTFIXUpdate Automation Studio to version 6.5 or later
Long-term hardening
0/2HARDENINGImplement network segmentation to restrict Automation Studio workstations to trusted communication paths and monitor for suspicious certificate usage
HARDENINGValidate server certificates using out-of-band methods before establishing ANSL or OPC-UA connections in safety-critical applications
CVEs (1)
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API:
/api/v1/advisories/f3f4afdb-60be-43e9-9338-591850df7e8f