TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH & Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.
A workaround or mitigation is available. Apply it until an official patch is released.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityUnreported
Vulnerable System
ConfidentialityNone
IntegrityNone
AvailabilityLow
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | cve.org | initial, patch: Mitigation | 1.7 |
Affected Software
| Vendor | Product | Version |
|---|
| Beckhoff | IPC Diagnostics UA Server | ≤ 3.1.0.1 |
| beckhoff | ipc_diagnostics_ua_server | ≤ 3.1.0.1 |
| Beckhoff | TF6100 | ≤ 3.3.18 |
| beckhoff | tf6100 | ≤ 3.3.18 |
| Beckhoff | TwinCAT OPC UA Server | ≤ 2.3.0.12 |
| beckhoff | twincat_opc_ua_server | ≤ 2.3.0.12 |
Published: 2021-05-13
