CVE-2025-56106 is an OS command injection vulnerability identified in the Ruijie RG-EW1800GX router firmware version B11P226_EW1800GX_10223121. The flaw exists in the handling of POST requests to the module_set function within the Lua script located at /usr/local/lua/dev_sta/nbr_cwmp.lua. Specifically, the vulnerability arises from improper input validation or sanitization of user-supplied data, allowing an attacker with low privileges (PR:L) to inject arbitrary operating system commands. The vulnerability can be exploited remotely over the network (AV:N) without requiring user interaction (UI:N), making it highly accessible to attackers. Successful exploitation compromises confidentiality, integrity, and availability (C:H/I:H/A:H) of the affected device, potentially enabling attackers to execute arbitrary commands, manipulate device configurations, intercept or disrupt network traffic, or pivot into internal networks. Although no public exploits are currently reported, the vulnerability's characteristics and high CVSS score (8.8) indicate a severe threat. The CWE-78 classification confirms this is a classic OS command injection issue, often resulting from unsafe command construction or insufficient input validation in the Lua module. The vulnerability was reserved in August 2025 and published in December 2025, indicating recent discovery and disclosure. No patches or mitigations are currently linked, emphasizing the need for immediate defensive measures.

For European organizations, this vulnerability poses a significant risk especially to those deploying Ruijie RG-EW1800GX routers in critical network segments such as enterprise gateways, branch offices, or industrial control systems. Exploitation could lead to full device compromise, allowing attackers to intercept sensitive communications, disrupt network availability, or use the device as a foothold for lateral movement within corporate networks. Confidential data could be exposed or altered, and network reliability could be severely impacted. Given the high severity and ease of exploitation, organizations relying on these devices without proper segmentation or monitoring face elevated risks of espionage, sabotage, or ransomware attacks. The lack of known public exploits currently provides a small window for proactive defense, but the potential impact on confidentiality, integrity, and availability is critical. This is especially concerning for sectors such as finance, healthcare, government, and critical infrastructure in Europe, where network security is paramount.

1. Immediately identify and isolate all Ruijie RG-EW1800GX devices within the network. 2. Restrict management interfaces to trusted IP addresses and implement strict access control lists (ACLs) to limit exposure of the vulnerable module_set endpoint. 3. Employ network segmentation to separate vulnerable devices from sensitive internal networks and critical assets. 4. Monitor network traffic for anomalous POST requests targeting /usr/local/lua/dev_sta/nbr_cwmp.lua or suspicious command injection patterns. 5. Disable or restrict remote management features if not required. 6. Engage with Ruijie support or vendors for firmware updates or patches as soon as they become available. 7. Implement intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting command injection attempts. 8. Conduct regular security audits and penetration tests focusing on network devices to identify similar vulnerabilities. 9. Educate network administrators on the risks and signs of exploitation related to this vulnerability. 10. Prepare incident response plans to quickly isolate and remediate affected devices if exploitation is detected.