CVE-2026-51705 in TOTOLINK
Summary
by MITRE • 08/31/2026
Incorrect access control in the setWiFiMeshName function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to rename mesh entries via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
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Analysis
by VulDB Data Team • 08/31/2026
The vulnerability identified in the setWiFiMeshName function within TOTOLINK T6 firmware version 4.1.5cu.748_B20211015 represents a critical failure in access control mechanisms, specifically classified under CWE-284 Improper Access Control. This flaw allows unauthenticated attackers to execute administrative functions that should be restricted to authorized users with valid credentials. The core technical issue lies in the web server's handling of POST requests directed at the /cgi-bin/cstecgi.cgi endpoint. Instead of verifying session tokens, authentication cookies, or other identity proofs before processing commands related to mesh network configuration, the application blindly accepts and executes these inputs from any source on the network. This lack of validation permits remote attackers who can reach the device's management interface over the local area network to manipulate critical Wi-Fi settings without prior login.
From an operational perspective, this vulnerability enables significant disruption to network integrity and availability. An attacker with access to the same LAN segment as the router can rename mesh entries, which may lead to confusion for legitimate users attempting to connect to specific nodes in a multi-device mesh setup. More severely, if the renaming process triggers underlying configuration changes or resets that are not properly secured, it could result in denial of service conditions where clients lose connectivity to their designated access points. The ability to alter these parameters without authentication undermines the trust model of home and small office networks, potentially facilitating further attacks such as man-in-the-middle scenarios by confusing client devices about which node is legitimate or intended for connection.
This type of vulnerability aligns with MITRE ATT&CK techniques related to Initial Access and Persistence, particularly those involving exploitation of web application vulnerabilities to gain footholds within a network environment. By exploiting this flaw, an attacker can establish control over the router's configuration state without detection through standard login attempts. The impact extends beyond simple misconfiguration; it compromises the confidentiality and integrity of the network management plane. Attackers could potentially use this access point as a pivot for lateral movement into other devices on the private network if additional security controls are not in place, such as VLAN segmentation or strict firewall rules isolating the management interface from general user traffic.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary solution is to apply the vendor-provided firmware update that patches this specific access control bypass by implementing proper authentication checks within the setWiFiMeshName function before processing any POST requests. Until an official patch is available, administrators should restrict physical or logical access to the router's management interface using firewall rules that limit connectivity to trusted IP addresses only. Additionally, disabling remote administration features if not strictly necessary reduces the attack surface exposed to potential threats from untrusted network segments. Regular auditing of firmware versions and monitoring for unusual configuration changes can also help in detecting exploitation attempts early.