CVE-2025-34057 is a high-severity information disclosure vulnerability affecting Ruijie NBR series routers, specifically the NBR2000G, NBR1300G, and NBR1000 models. The vulnerability arises from improper authentication checks and insecure backend logic in the router's web management interface, particularly at the /WEB_VMS/LEVEL15/ endpoint. An unauthenticated attacker can exploit this flaw by sending a crafted POST request with modified Cookie headers and specially formatted parameters. This request bypasses authentication controls and causes the router to disclose administrative account credentials in plaintext. The vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) and CWE-306 (Missing Authentication for Critical Function). The CVSS v4.0 base score is 8.7, reflecting its critical impact and ease of exploitation without any required privileges or user interaction. Although no public exploits have been reported in the wild yet, the vulnerability's nature makes it a prime target for attackers seeking to gain unauthorized administrative access to affected routers. This could lead to further network compromise, interception of sensitive data, or persistent unauthorized control over network infrastructure. The lack of available patches at the time of reporting increases the urgency for affected organizations to implement interim mitigations and monitor for suspicious activity.

For European organizations, this vulnerability poses significant risks due to the potential exposure of administrative credentials for critical network infrastructure devices. Compromise of these routers could allow attackers to manipulate network traffic, intercept confidential communications, or establish persistent footholds within corporate or governmental networks. Given that Ruijie routers are used in various sectors including enterprise, education, and public administration, the impact could extend to disruption of services, data breaches, and loss of trust. The vulnerability's ability to be exploited remotely without authentication means attackers can operate from outside the network perimeter, increasing the threat to organizations with internet-facing management interfaces. Additionally, exposure of plaintext credentials undermines confidentiality and integrity, potentially facilitating lateral movement and further exploitation within affected networks. The absence of known exploits currently provides a window for proactive defense, but the high CVSS score indicates that once exploited, the consequences could be severe.

1. Immediate Network Segmentation: Restrict access to the router management interfaces by implementing strict network segmentation and firewall rules to allow only trusted administrative hosts to connect to the management endpoints. 2. Disable Remote Management: If remote management is not essential, disable it entirely to prevent external exploitation. 3. Monitor Network Traffic: Deploy intrusion detection systems (IDS) and monitor for anomalous POST requests targeting the /WEB_VMS/LEVEL15/ endpoint or unusual cookie header modifications. 4. Credential Rotation: As a precaution, rotate administrative credentials on all affected devices to limit exposure in case of compromise. 5. Vendor Engagement: Engage with Ruijie support channels to obtain patches or firmware updates as soon as they become available. 6. Incident Response Preparation: Prepare incident response plans to quickly isolate and remediate affected devices if exploitation is detected. 7. Access Logging and Auditing: Enable detailed logging on routers to capture access attempts and facilitate forensic analysis. 8. Use VPN or Secure Channels: When remote management is necessary, enforce access through secure VPN tunnels or encrypted management protocols to reduce exposure.