PT-2021-5257 · Beckhoff · Twincat Opc Ua Server+1

Published 2021-05-13 · Updated 2021-05-25 · CVE-2020-12526

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions TwinCAT OPC UA Server versions up to 2.3.0.12 IPC Diagnostics UA Server versions up to 3.1.0.1

Description The issue exists due to insufficient input validation, allowing a remote attacker to cause a denial of service. This can be achieved by sending several specifically crafted requests to the running OPC UA server, after which the server is no longer responsive to any client. The real-time functionality of IPCs remains unaffected.

Recommendations For TwinCAT OPC UA Server versions up to 2.3.0.12, update to a version later than 2.3.0.12 to resolve the issue. For IPC Diagnostics UA Server versions up to 3.1.0.1, update to a version later than 3.1.0.1 to resolve the issue. As a temporary workaround, consider restricting access to the OPC UA server to minimize the risk of exploitation.

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

BDU:2021-06083

CVE-2020-12526

Affected Products

Ipc Diagnostics Ua Server

Twincat Opc Ua Server

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2020-12526 · Security Note
• https://download.beckhoff.com/download/Document/product-security/Advisories/advisory-2021-001.pdf · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2020-12526 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-06083 · Security Note
• https://cert.vde.com/en-us/advisories/vde-2020-051 · Note
• https://t.me/cvenotify/14383 · Telegram Post