The RCU II+ and Multiload II+ are vulnerable to an unauthenticated
service that exposes a debug interface granting full root-level access
to the embedded system. This vulnerability stems from a
network-accessible port running a Target Communications Framework (TCF)
service that does not require any authentication, allowing an attacker
to directly interact with the Linux environment that powers the device.
Once connected, an attacker can freely view and modify the filesystem,
manipulate running processes, and control network interfaces, enabling
deep alteration of system behavior.
Attack Parameters
Attack Vector
Adjacent
Requires local network access
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 6
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-2…
ics-cert@hq.dhs.gov
https://s3.amazonaws.com/docs.toptech.com/index.html#downloads/Firmware/RCUII+_…
ics-cert@hq.dhs.gov
https://s3.amazonaws.com/docs.toptech.com/nonpublic/2025%2012%2001%20RCU%20IIPl…
ics-cert@hq.dhs.gov
https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.gz
ics-cert@hq.dhs.gov
https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.zip
ics-cert@hq.dhs.gov
https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-03
ics-cert@hq.dhs.gov