CVE-2026-19971 in WR1210M
Summary
by MITRE • 08/17/2026
A flaw has been found in LB-Link WR1210M 1.0.3. This impacts the function main of the file /www/cgi-bin/backup.cgi of the component Backup Endpoint. This manipulation causes missing authentication. The attack is only possible within the local network. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 08/24/2026
The vulnerability identified in LB-Link WR1210M firmware version 1.0.3 represents a critical security deficiency within the device's web management interface, specifically affecting the backup functionality endpoint located at /www/cgi-bin/backup.cgi. This flaw is categorized as a missing authentication issue, which fundamentally undermines the integrity of access controls governing sensitive administrative operations. In typical router architectures, functions related to system configuration backups and restores are privileged actions that require verified user credentials due to their potential impact on network security posture. However, in this specific implementation, the main function handling these requests fails to enforce any form of authentication or session validation before executing the backup process. This oversight allows any entity capable of reaching the web server interface to invoke the backup endpoint without providing valid login details, thereby bypassing established security boundaries designed to protect administrative data.
From a technical perspective, this vulnerability aligns with CWE-306, which describes Missing Authentication for Critical Function. The absence of authentication checks means that the application does not verify whether the requesting user has been properly authenticated by the system before processing the request. This is often caused by developers assuming that because the web interface itself requires login to access most pages, all underlying CGI scripts are implicitly protected or that session tokens are correctly validated for every endpoint. In this case, the backup.cgi script operates independently of these checks, creating a direct path for unauthorized data exfiltration. The vulnerability stems from an implementation error where security controls were not uniformly applied across all administrative functions within the web server's execution environment.
The operational impact of this flaw is significant despite its limitation to local network attacks. An attacker positioned on the same LAN segment as the vulnerable router can exploit this weakness to retrieve full configuration backups without any prior authorization. These backup files typically contain plaintext or easily decryptable credentials, including Wi-Fi passwords, administrative login hashes, ISP connection details, and potentially custom firewall rules or DNS settings. The acquisition of such data allows an attacker to perform offline cracking attacks against captured password hashes, leading to complete compromise of the router's administration panel. Furthermore, possession of these configuration files enables sophisticated network reconnaissance, allowing the attacker to map out internal IP schemes, identify connected devices, and understand the security policies in place, which facilitates further lateral movement or targeted attacks within the local infrastructure.
This vulnerability is also relevant to MITRE ATT&CK framework techniques related to Credential Access and Discovery. Specifically, it relates to T1087 Account Discovery and T1552 Unsecured Credentials, as the attacker gains access to sensitive information that can be used for subsequent unauthorized access. The limitation of this attack vector to local network boundaries means that remote exploitation over the internet is not directly possible unless other vulnerabilities exist or if the router's web interface has been inadvertently exposed via port forwarding misconfigurations by a previous administrator. However, in environments where trusted devices are connected to untrusted networks, such as public Wi-Fi hotspots with poor isolation or compromised internal endpoints, this local-only constraint offers limited protection against determined adversaries who have already gained foothold within the network perimeter.
Mitigation strategies for this vulnerability primarily involve updating the firmware if a patched version is released by LB-Link, although reports indicate that vendor responsiveness has been lacking in previous disclosures. In the absence of an official patch, administrators should implement compensating controls to reduce risk. Network segmentation is crucial; placing routers behind additional layers of security or restricting access to management interfaces via VLANs can limit exposure. Additionally, changing default credentials and disabling remote management features are standard best practices that may indirectly mitigate some risks, though they do not fix the underlying code flaw. For organizations relying on this hardware, continuous monitoring for firmware updates is essential, and consideration should be given to replacing devices from vendors with poor security track records if alternative models offering regular security maintenance are available. Until a patch is provided, treating any device running version 1.0.3 as potentially compromised within local network contexts is advisable due to the ease of data extraction afforded by this authentication bypass.