CVE-2021-34594: beckhoff automation twincat opc ua server Relative Path Traversal
CVSS: 8.5v2.0HighModified
Published 04-11-2021Last modified 16-09-2024
Vulnerability summary
CVE-2021-34594 is a high (CVSS 8.5) Relative Path Traversal vulnerability in beckhoff automation twincat opc ua server. EPSS estimates a 1.13% chance of exploitation in the next 30 days, higher than 66% of scored vulnerabilities.
CVSS score
8.5/10
010
High · v2.0 (NVD)EPSS score
1.13%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 04-11-2021PublishedVulnerability first disclosed.
- 16-09-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 2 sources · 2 versionsMedium 6.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:HSourcesAll 2 agree
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
High 8.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:S/C:N/I:C/A:CSourcesSingle source
EPSS trend
Probability
1.13%
Chance of exploitation in the next 30 days
Percentile
66%
Versus all other CVEs
30-day change
0.00 pp
From 1.13% on 21-09-2026
21-09-202621-10-2026
EPSS score1.13%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-23Relative Path TraversalThe product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.
- CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Affected systems
Beckhoff2 products
- tf6100_firmware< 4.3.48.0
- ts6100_firmware< 4.3.48.0
Beckhoff automation1 product
- twincat opc ua server≥ TF6100, < 4.3.48.0 | ≥ TS6100, < 4.3.48.0 | ≥ TcOpcUaServer version, < 3.2.0.19423
2 vendors · 3 products