Beckhoff's TwinCAT RT network driver for Intel 8254x and 8255x is providing EtherCAT functionality. The driver implements real-time features. Except for Ethernet frames sent from real-time functionality, all other Ethernet frames sent through the driver are not padded if their payload is less than the minimum Ethernet frame size. Instead, arbitrary memory content is transmitted within in the padding bytes of the frame. Most likely this memory contains slices from previously transmitted or received frames. By this method, memory content is disclosed, however, an attacker can hardly control which memory content is affected. For example, the disclosure can be provoked with small sized ICMP echo requests sent to the device.

Beckhoff TwinCAT supports communication over ADS. ADS is a protocol for industrial automation in protected environments. ADS has not been designed to achieve security purposes and therefore does not include any encryption algorithms because of their negative effect on performance and throughput. An attacker can forge arbitrary ADS packets when legitimate ADS traffic is observable.

Beckhoff Embedded PC images before 2014-10-22 and Automation Device Specification (ADS) TwinCAT components might allow remote attackers to obtain access via the (1) Windows CE Remote Configuration Tool, (2) CE Remote Display service, or (3) TELNET service.

Beckhoff Embedded PC images before 2014-10-22 and Automation Device Specification (ADS) TwinCAT components do not restrict the number of authentication attempts, which makes it easier for remote attackers to obtain access via a brute-force attack.

Beckhoff TwinCAT 2.11.0.2004 and earlier allows remote attackers to cause a denial of service via a crafted request to UDP port 48899, which triggers an out-of-bounds read.