CVE-2025-57278 is a critical vulnerability affecting the LB-Link BL-CPE300M AX300 4G LTE Router, specifically in the firmware version BL-R8800_B10_ALK_SL_V01.01.02P42U14_06. The root cause of this vulnerability lies in improper session handling mechanisms. After a legitimate user authenticates from a particular IP address, the router erroneously grants administrative access to any other client that presents the same IP address, without requiring further authentication or verifying the client’s identity. This is due to the absence of session tokens, cookies, or any unique session identifiers to differentiate between authenticated and unauthenticated clients. Consequently, an attacker can bypass authentication entirely by spoofing or configuring their device to use the same IP address as a previously authenticated user. This results in a complete authentication bypass, granting the attacker full administrative control over the router. The vulnerability is classified under CWE-287 (Improper Authentication) and has a CVSS v3.1 base score of 8.8, indicating a high severity level. The attack vector is adjacent network (AV:A), requiring no privileges or user interaction, and impacts confidentiality, integrity, and availability at a high level. No known exploits are currently reported in the wild, and no official patches have been linked yet. This flaw poses significant risks including unauthorized configuration changes, interception or redirection of network traffic, and potential pivoting into internal networks.

For European organizations, this vulnerability presents a substantial risk, especially for enterprises and service providers relying on LB-Link BL-CPE300M AX300 routers for 4G LTE connectivity. The authentication bypass allows attackers to gain full administrative access remotely if they can spoof or share the same IP address as an authenticated user, which is feasible in environments where IP addresses are dynamically assigned or shared, such as in certain ISP configurations or VPNs. The impact includes potential exposure of sensitive network configurations, interception of internal communications, deployment of malicious firmware or backdoors, and disruption of network availability. This could lead to data breaches, espionage, or denial of service, severely affecting business operations and compliance with European data protection regulations such as GDPR. The vulnerability is particularly critical for organizations with remote or mobile workforce setups relying on LTE routers for connectivity, as attackers could exploit this flaw to compromise network integrity without physical access or complex attack chains.

Given the lack of official patches, European organizations should implement immediate compensating controls. First, restrict access to the router’s management interface to trusted IP addresses and networks using firewall rules or VPNs to minimize exposure. Disable remote management features unless absolutely necessary and enforce strong network segmentation to isolate the router management network from critical assets. Monitor network logs for unusual IP address reuse or multiple administrative sessions originating from the same IP. Employ network-level authentication and encryption mechanisms such as IPsec or SSL/TLS tunnels to protect management traffic. Where possible, replace affected routers with models from vendors with robust security track records and timely patching policies. Additionally, coordinate with LB-Link and ISPs to obtain firmware updates or advisories. Educate network administrators about the risks of IP address spoofing and session hijacking to enhance operational vigilance.