CVE-2022-25622 is a vulnerability identified in the Siemens SIMATIC CFU DIQ product, specifically related to its PROFINET (PNIO) stack when integrated with the Interniche IP stack. The issue arises from improper handling of internal resources for TCP segments that have a TCP header length smaller than the defined minimum. TCP headers have a minimum length of 20 bytes, and segments with headers shorter than this violate protocol standards. The vulnerability is classified under CWE-400, indicating uncontrolled resource consumption. An attacker can exploit this by sending specially crafted TCP segments with undersized headers, causing the affected device to improperly allocate or fail to release resources. This leads to resource exhaustion, resulting in a denial of service (DoS) condition for TCP services hosted on the device. The vulnerability does not require authentication or user interaction, making it potentially exploitable remotely by any attacker capable of sending TCP packets to the device. Although no known exploits have been reported in the wild, the vulnerability's nature means it could disrupt critical industrial network communications, as SIMATIC CFU DIQ devices are used in industrial automation environments. The lack of a patch at the time of reporting increases the risk for affected deployments. The vulnerability impacts the availability of services by exhausting resources, but does not directly compromise confidentiality or integrity. The affected product is specialized industrial control equipment, often deployed in manufacturing and critical infrastructure sectors.

For European organizations, the impact of CVE-2022-25622 could be significant, particularly for those operating industrial automation and control systems that rely on Siemens SIMATIC CFU DIQ devices. These devices are commonly used in manufacturing plants, energy production, and critical infrastructure sectors such as utilities and transportation. A successful exploitation could lead to denial of service conditions, disrupting TCP-based communications essential for process control and monitoring. This could cause operational downtime, production losses, safety risks, and potential cascading effects on supply chains. Given the critical role of industrial control systems in Europe’s manufacturing-heavy economies and critical infrastructure, the vulnerability poses a risk to operational continuity and safety. Although the vulnerability does not allow direct data compromise, the availability impact alone can have severe economic and safety consequences. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers often target industrial control systems. The medium severity rating reflects the balance between the potential impact and the technical complexity of exploitation.

Implement network segmentation to isolate SIMATIC CFU DIQ devices from general IT networks, limiting exposure to untrusted sources. Deploy strict firewall rules to restrict inbound TCP traffic to only trusted management and control systems, minimizing attack surface. Monitor network traffic for anomalous TCP segments, particularly those with abnormal header lengths or malformed packets, using intrusion detection systems (IDS) or industrial protocol analyzers. Apply vendor-provided updates or patches as soon as they become available; if no patch exists, engage Siemens support for recommended workarounds or mitigations. Use rate limiting or TCP packet filtering at network ingress points to prevent flooding of malformed TCP segments targeting the affected devices. Conduct regular security assessments and penetration testing focused on industrial control systems to identify and remediate similar vulnerabilities. Maintain an incident response plan tailored to industrial environments to quickly address potential denial of service events.