CVE-2025-41224: Siemens RUGGEDCOM Auth Bypass Flaw

CVE-2025-41224 Overview

Siemens disclosed CVE-2025-41224, an improper protection mechanism flaw [CWE-693] affecting a wide range of RUGGEDCOM ROS devices running firmware versions earlier than V5.10.0. The affected switches and serial servers fail to enforce interface access restrictions when an administrator reconfigures an interface from management to non-management. The configuration change is saved, but the running access control state persists until the device reboots. An attacker with adjacent network access and valid credentials can connect to the device through the supposedly non-management interface and maintain SSH access until a reboot occurs.

Critical Impact

Authenticated attackers on an adjacent network can retain SSH management access to RUGGEDCOM industrial network devices despite configuration changes intended to restrict access.

Affected Products

• RUGGEDCOM RMC8388 / RMC8388NC V5.X (all versions < V5.10.0)
• RUGGEDCOM RS416v2, RS416Pv2, RS416NCv2, RS416PNCv2 V5.X (all versions < V5.10.0)
• RUGGEDCOM RS900/RS900G/RSG2100/RSG2288/RSG2300/RSG2488/RSG907R/RSG908C/RSG909R/RSG910C/RSG920P series, RSL910, RST2228/RST2228P, RST916C/RST916P (all versions < V5.10.0)

Discovery Timeline

• 2025-07-08 - CVE-2025-41224 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-41224

Vulnerability Analysis

The vulnerability resides in how RUGGEDCOM ROS applies interface role changes. RUGGEDCOM ROS distinguishes between management interfaces, which permit administrative protocols such as SSH, and non-management interfaces, which should reject those protocols. When an operator reclassifies an interface from management to non-management, ROS commits the change to persistent configuration but does not tear down or re-evaluate existing service bindings on that interface. The enforcement gap persists until the next system reboot.

This behavior maps to [CWE-693] Protection Mechanism Failure. The control plane reports the interface as non-management, yet the data plane continues to honor management traffic on it. Operators who change configuration to revoke access from a compromised or untrusted segment retain a false sense of remediation.

Root Cause

The root cause is incomplete enforcement of access control state transitions. Interface role changes update stored configuration without restarting the SSH listener or refreshing the firewall ruleset bound to that interface. The runtime continues using the previously evaluated access policy until initialization runs again at boot.

Attack Vector

An attacker must have adjacent network reachability to the affected interface and possess valid device credentials. After an administrator demotes the interface from management to non-management, the attacker can still initiate SSH sessions through that interface and authenticate normally. Existing sessions are not terminated. The attacker retains full administrative control of the RUGGEDCOM device until a reboot reinitializes the access policy.

No verified public exploit code is available. Technical specifics are documented in the Siemens Security Advisory SSA-083019.

Detection Methods for CVE-2025-41224

Indicators of Compromise

• SSH session establishment on RUGGEDCOM interfaces recently reconfigured as non-management, without an intervening device reboot.
• Authentication success events from source IPs residing in network segments that are no longer authorized for management access.
• Active management sessions visible in show users or session telemetry that originate from interfaces marked non-management in current configuration.

Detection Strategies

• Correlate RUGGEDCOM configuration change events with subsequent SSH connection logs to flag access through demoted interfaces prior to reboot.
• Baseline expected management source subnets and alert on administrative authentication from unexpected adjacent VLANs or interfaces.
• Audit running-state versus saved-state divergence by comparing active service bindings against the current interface role configuration.

Monitoring Recommendations

• Forward RUGGEDCOM syslog (authentication, configuration, and session events) to a central SIEM and retain for incident review.
• Monitor uptime counters on RUGGEDCOM devices and flag long uptime values following interface reclassification changes.
• Alert on SSH connections sourced from operational technology (OT) segments that should not contain management workstations.

How to Mitigate CVE-2025-41224

Immediate Actions Required

• Upgrade affected RUGGEDCOM ROS devices to firmware V5.10.0 or later as published by Siemens.
• Reboot any device where an interface has been changed from management to non-management to force re-evaluation of access policies.
• Restrict adjacent network access to RUGGEDCOM management planes using upstream ACLs, dedicated management VLANs, and network segmentation.
• Rotate device credentials if a demoted interface was exposed to untrusted segments before reboot.

Patch Information

Siemens has released ROS V5.10.0 to remediate CVE-2025-41224 across the affected product families. Refer to the Siemens Security Advisory SSA-083019 for the authoritative list of fixed versions and download instructions.

Workarounds

• Schedule a reboot immediately after any interface role change to ensure enforcement of the new configuration.
• Enforce strong, unique credentials and disable unused accounts to limit the population of users who could exploit the residual access.
• Place RUGGEDCOM devices behind a hardened jump host and require multi-factor authentication at the bastion layer.
• Apply Siemens operational guidelines for industrial security, including defense-in-depth across the cell and perimeter networks.

# After changing an interface from management to non-management on RUGGEDCOM ROS,
# commit the configuration and force a reboot so the access policy is reapplied.

save
reboot