Beckhoff TwinCAT RT Network Driver Incomplete Cleanup (CVE-2020-12494)

medium Tenable OT Security Plugin ID 500466

Synopsis

The remote OT asset is affected by a vulnerability.

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.

This plugin only works with Tenable.ot. Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

See Also

http://www.nessus.org/u?1712f911

https://cert.vde.com/en-us/advisories/vde-2020-019

Plugin Details

Severity: Medium

ID: 500466

Version: 1.4

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 9/12/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 1.4

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2020-12494

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:beckhoff:twincat

Required KB Items: Tenable.ot/Beckhoff

Exploit Ease: No known exploits are available

Patch Publication Date: 6/16/2020

Vulnerability Publication Date: 6/16/2020

Reference Information

CVE: CVE-2020-12494

CWE: 459