CVE-2020-12526 json
BECKHOFF: DoS-Vulnerability for TwinCAT OPC UA Server and IPC Diagnostics UA Server
published 2021-05-13 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-4828
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 61%
- public exploits
- 0
- none known
Summary
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.
Exploit prediction
0.95% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Affected products
- Beckhoff TwinCAT OPC UA Server
- Beckhoff IPC Diagnostics UA Server
- Beckhoff TF6100
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
download.beckhoff.com
/download/Document/product-security/Advisories/advisory-2021-001.pdf
vendor-advisory
-
cert.vde.com
/en-us/advisories/vde-2020-051
third-party-advisory
Sources
- CVE List CVE-2020-12526
- NVD CVE-2020-12526
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