Unauthenticated arbitrary file operations via relative path traversal
Published Nov 4, 2021 · Updated Sep 16, 2024
Relative path traversal in Beckhoff TwinCAT OPC UA Server before 4.3.48.0 allows remote attackers to create or delete arbitrary system files. In TcOpcUaServer before 3.2.0.19423, configuration namespace nodes accept filenames containing relative paths without sanity checks, escaping dedicated directories. The default installation permits anonymous access to these administrative nodes, so no account is required to alter or remove files reachable by the server process.
Summary
What happened
Relative path traversal in Beckhoff TwinCAT OPC UA Server before 4.3.48.0 allows remote attackers to create or delete arbitrary system files. In TcOpcUaServer before 3.2.0.19423, configuration namespace nodes accept filenames containing relative paths without sanity checks, escaping dedicated directories. The default installation permits anonymous access to these administrative nodes, so no account is required to alter or remove files reachable by the server process.
The record
- CVE
- CVE-2021-34594
- Published
- Nov 4, 2021
- Updated
- Sep 16, 2024
- Vendor
- Beckhoff Automation GmbH & Co. KG
- Product
- TwinCAT OPC UA Server
- Classifications
- CWE-23, T1070.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 4, 2021CVE publishedPublication date reported by the CVE source.
- Sep 16, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=TcOpcUaServer version <3.2.0.19423
- Affected versionversion=TF6100 <4.3.48.0
- Affected versionversion=TS6100 <4.3.48.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo