CVE-2025-41222 is a vulnerability identified in a broad range of Siemens RUGGEDCOM devices, including models i800, i801, i802, i803, M2100, M2200, M969, RMC30, RMC8388, RP110, RS1600 series, RS400 series, RS8000 series, RS900 series, RS910 series, RS920 series, RS930 series, RS940G, RS969, RSG2100 series, RSG2200, RSG2288, RSG2300 series, RSG2488, RSG907R, RSG908C, RSG909R, RSG910C, RSG920P, RSL910, RST2228 series, and RST916 series. The vulnerability stems from improper handling of exceptional conditions, specifically malformed TLS handshake messages by the embedded webserver on these devices. When an attacker with network access sends malformed TLS handshake messages, the device fails to handle these exceptions correctly, leading to a denial of service (DoS) condition. This DoS causes the webserver and the device itself to crash, potentially disrupting network communications and device operations. The vulnerability is classified under CWE-755, which relates to improper handling of exceptional conditions. The CVSS v3.1 base score is 5.3 (medium severity), with vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L, indicating network attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, no confidentiality or integrity impact, but availability impact due to service disruption. No known exploits are currently reported in the wild, and no patches are linked yet. The affected devices are widely used in industrial and critical infrastructure networks, often deployed in harsh environments requiring ruggedized communication equipment. The vulnerability could be exploited remotely by unauthenticated attackers with network access to the device's webserver port, making it a significant risk for operational continuity.

For European organizations, especially those in critical infrastructure sectors such as energy, transportation, manufacturing, and utilities, this vulnerability poses a risk of operational disruption. Siemens RUGGEDCOM devices are commonly deployed in industrial control systems (ICS) and operational technology (OT) networks across Europe. A successful DoS attack could cause network outages, loss of monitoring and control capabilities, and potential cascading effects on industrial processes. While the vulnerability does not allow data theft or manipulation, the availability impact can lead to safety risks, financial losses, and regulatory non-compliance, particularly under EU directives like NIS2 that mandate cybersecurity resilience for essential services. The fact that no authentication or user interaction is required increases the risk, as attackers can exploit the vulnerability remotely if they gain network access. This is particularly concerning in environments where network segmentation is weak or remote access is enabled without adequate controls. The medium CVSS score reflects the limited scope to availability impact only, but the critical nature of affected systems elevates the practical severity for European critical infrastructure operators.

1. Network Segmentation: Isolate RUGGEDCOM devices on dedicated network segments with strict access controls to limit exposure to untrusted networks. 2. Access Control: Restrict network access to the webserver interface of RUGGEDCOM devices using firewalls, VPNs, or jump hosts to prevent unauthorized access. 3. Monitoring and Detection: Implement network monitoring to detect anomalous TLS handshake patterns or repeated malformed packets targeting these devices. 4. Vendor Updates: Regularly check Siemens advisories for patches or firmware updates addressing this vulnerability and apply them promptly once available. 5. Incident Response Planning: Prepare response procedures for DoS incidents affecting RUGGEDCOM devices, including failover mechanisms and manual control options. 6. Harden TLS Configuration: Where possible, configure devices to use robust TLS versions and cipher suites, and disable legacy protocols that may be more susceptible to malformed handshake exploitation. 7. Network Access Controls: Employ intrusion prevention systems (IPS) or deep packet inspection (DPI) to block malformed TLS handshake attempts targeting these devices. 8. Vendor Engagement: Engage Siemens support for guidance and potential workarounds until patches are released. These steps go beyond generic advice by focusing on network-level controls, device-specific configurations, and operational preparedness tailored to the industrial context of RUGGEDCOM devices.