Executive brief
A vulnerability exists in several Siemens industrial routers and security modules used to provide secure remote access to factory networks. The affected devices do not correctly verify usernames when using OpenVPN, which could allow an unauthorized person to bypass certain credential checks. While this flaw is difficult to exploit, it could potentially allow an attacker to gain unauthorized access to the network or disrupt secure communications.
Technical details
The vulnerability is classified as a partial string comparison (CWE-187) within the OpenVPN authentication component of various Siemens industrial networking products. Affected devices fail to properly validate the full username string during the authentication handshake. A remote, unauthenticated attacker could exploit this by providing a specifically crafted, partial username that the server incorrectly accepts as valid. Successful exploitation requires high complexity (AC:H) but could lead to unauthorized access or integrity issues within the VPN tunnel. Siemens has released firmware updates (V8.2.1 for M-800/RM1224 and V3.2 for SC-600) to address the issue.
Affected products
- Siemens RUGGEDCOM RM1224 LTE(4G) EU < V8.2.1
- Siemens RUGGEDCOM RM1224 LTE(4G) NAM < V8.2.1
- Siemens SCALANCE M804PB < V8.2.1
- Siemens SCALANCE M812-1 ADSL-Router family < V8.2.1
- Siemens SCALANCE M816-1 ADSL-Router family < V8.2.1
- Siemens SCALANCE M826-2 SHDSL-Router < V8.2.1
- Siemens SCALANCE M874-2 < V8.2.1
- Siemens SCALANCE M874-3 < V8.2.1
- Siemens SCALANCE M876-3 < V8.2.1
- Siemens, SCALANCE M876-4 < V8.2.1
- Siemens SCALANCE MUB852-1 < V8.2.1
- Siemens SCALANCE MUM853-1 < V8.2.1
- Siemens SCALANCE MUM856-1 < V8.2.1
- Siemens SCALANCE S615 EEC LAN-Router < V8.2.1
- Siemens SCALANCE S615 LAN-Router < V8.2.1
- Siemens SCALANCE SC622-2C < V3.2
- Siemens SCALANCE SC626-2C < V3.2
- Siemens SCALANCE SC632-2C < V3.2
- Siemens SCALANCE SC636-2C < V3.2
- Siemens SCALANCE SC642-2C < V3.2
- Siemens SCALANCE SC646-2C < V3.2
Timeline
- 2025-03-11: advisory: Initial publication by Siemens and NVD
- 2026-05-12: other: Last update to the advisory record