CVE-2026-51613 in TOTOLINK
Summary
by MITRE • 08/28/2026
Incorrect access control in the getDeviceInfo function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to obtain device identification details via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
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Analysis
by VulDB Data Team • 08/28/2026
The vulnerability identified in the getDeviceInfo function of TOTOLINK T6 router 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 remote attackers to retrieve sensitive device identification details by interacting with the web management interface at /cgi-bin/cstecgi.cgi via crafted POST requests. The core technical issue lies in the absence of proper authentication checks or session validation within this specific CGI endpoint, which is intended for administrative functions but remains accessible to any network user without valid credentials. This misconfiguration effectively bypasses the security boundary that should restrict such operations to authorized administrators only, exposing internal system metadata to external observers.
From an operational perspective, the ability to extract device identification details can serve as a significant reconnaissance vector for potential attackers. While obtaining basic hardware or firmware identifiers may seem benign in isolation, it provides valuable intelligence for crafting targeted attacks against specific router models and software versions. Attackers can use this information to identify known vulnerabilities associated with that exact firmware build, facilitating more precise exploitation attempts. Furthermore, the exposure of internal network topology details or unique device signatures can aid in lateral movement within a compromised local area network, as it helps attackers map out connected devices and understand the specific environment they are operating in. This aligns with the ATT&CK technique T1087 Endpoint Discovery, where adversaries gather information about the system to plan further intrusions.
The exploitation of this vulnerability requires only basic networking knowledge and does not necessitate prior authentication or complex payload construction beyond a standard HTTP POST request directed at the vulnerable CGI script. This low barrier to entry significantly increases the risk profile, as automated scanning tools can easily detect and exploit such misconfigurations across large segments of internet-connected devices. The persistence of this flaw in production firmware highlights potential gaps in the development lifecycle security testing processes, particularly regarding input validation and authorization checks for administrative endpoints that are exposed over HTTP interfaces.
To mitigate this vulnerability, immediate action should be taken to apply any available firmware updates from TOTOLINK that address this access control issue. If an update is not yet available, network administrators can implement temporary compensating controls by restricting access to the router's web management interface through firewall rules or VLAN segmentation, ensuring that only trusted IP addresses can reach /cgi-bin/cstecgi.cgi. Additionally, disabling remote administration features if they are not strictly necessary reduces the attack surface exposed to untrusted networks. Long-term remediation requires developers to enforce strict authentication and authorization checks on all administrative CGI endpoints, ensuring that sensitive functions like getDeviceInfo require valid session tokens or credentials before processing requests. Adhering to secure coding standards such as OWASP Top 10 guidelines for broken access control is essential to prevent similar issues in future firmware releases.