CVE-2020-12526 — BECKHOFF: DoS-Vulnerability for TwinCAT OPC UA Server and IPC Diagnostics UA Server

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.

Published May 13, 2021Updated Sep 16, 2024Sources: cvelistV5, CERTVDE

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

beckhoff

3 products listed

CVSS base

5.3

MEDIUM

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

beckhoff

Products (3)

twincat opc ua serveripc diagnostics ua servertf6100

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
5.3	CVSS 3.1	MEDIUM	—	—	cvelistV5

Weakness & attack patterns

CWE-20

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

T1562.003Impair Defenses: Impair Command History Logging
T1574.006Hijack Execution Flow: Dynamic Linker Hijacking
T1574.007Hijack Execution Flow: Path Interception by PATH Environment Variable

References

2 on the record

cert.vde.com/en-us/advisories/vde-2020-051
x_refsource_CONFIRM
download.beckhoff.com/download/Document/product-security/Advisories/advisory-2021-001.pdf
x_refsource_CONFIRM

Elsewhere on this site

beckhoffevery CVE for this vendor
CWE-20other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.