CVE-2026-109439: Lantronix XPress-DR 8.1.0.0 Unauthenticated Configuration Write via UDP 30718
Lantronix XPress-DR and XPress-DR-I (CoBos-family) firmware through 8.1.0.0 contains a missing authentication vulnerability that allows remote attackers to read and persistently overwrite device configuration by sending crafted frames to the unauthenticated UDP configuration protocol on port 30718. Attackers can send a type 0xF8 query to read live configuration data and a type 0xFD frame with exactly 0x78 body bytes to rewrite the device IP address and serial-channel forwarding records, causing changes to commit to EEPROM and persist across reboots. The XPress-DR product series reached end-of-life/end-of-support in February 2025.
Affected Software
Event History
Frequently Asked Questions
Which devices are exposed to remote attack?
Lantronix XPress-DR and XPress-DR-I devices running CoBos-family firmware through 8.1.0.0 are exposed when an attacker can send UDP traffic to port 30718. No authentication or prior privileges are required.
What can an unauthenticated attacker change?
An attacker can send a type 0xFD frame containing exactly 0x78 body bytes to rewrite the device IP address and serial-channel forwarding records. The changes are committed to EEPROM and remain in place after rebooting the device.
Can this be used to obtain configuration information before making changes?
Yes. A type 0xF8 query can retrieve live configuration data through the same unauthenticated UDP configuration protocol.
Is vendor support likely to provide a remediation?
The XPress-DR product series reached end-of-life and end-of-support in February 2025. The provided information identifies affected firmware through 8.1.0.0 but does not identify a fixed version.