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Fencer Vulns
medium 6.5

CVE-2021-34594 json

Beckhoff: Relative path traversal vulnerability through TwinCAT OPC UA Server

published 2021-11-04 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21244

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

TwinCAT OPC UA Server in TF6100 and TS6100 in product versions before 4.3.48.0 or with TcOpcUaServer versions below 3.2.0.194 are prone to a relative path traversal that allow administrators to create or delete any files on the system.

Patch / fix

  • Beckhoff Automation TwinCAT OPC UA Server 3.2.0.19423, 4.3.48.0

Exploit prediction

1.13% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
NVD 2.0 8.5 AV:N/AC:L/Au:S/C:N/I:C/A:C

Affected products

  • Beckhoff Automation TwinCAT OPC UA Server

Classification

Weakness
  • CWE-23 Relative Path Traversal
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.