Executive brief
Hirschmann HiOS is the operating system used in industrial network switches and routers. A security flaw in how these devices process industrial communication traffic allows a remote attacker to crash or freeze the device by sending a specially crafted network packet. This could lead to a complete loss of network connectivity and disruption of industrial operations until the hardware is manually reset or recovered.
Technical details
A denial of service vulnerability exists in the EtherNet/IP stack of Hirschmann HiOS due to improper input validation (CWE-20) of packet length fields. An unauthenticated remote attacker can exploit this by sending specially crafted UDP EtherNet/IP packets where the declared length value is larger than the actual packet size. This mismatch causes the device to crash or hang, rendering it inoperable. The vulnerability is resolved in HiOS versions 08.1.00, 07.1.01, and later.
Affected products
- Hirschmann (Belden) HiOS Prior to 08.1.00 and 07.1.01
Timeline
- 2026-04-03: advisory: Initial advisory published by VulnCheck and Belden