Vulnerability record · CVE-2020-12494 · published 16 June 2020
CVE-2020-12494: Beckhoff twincat driver vulnerability
Beckhoff · Twincat Driver
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.
Description
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Affected products
2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://cert.vde.com/en-us/advisories/vde-2020-019 | Third Party Advisory |
| https://cert.vde.com/en-us/advisories/vde-2020-019 | Third Party Advisory |
Track CVE-2020-12494 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2020-12494), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
