CVE-2026-10137 in Totolink
Summary
by MITRE • 10/20/2026
A stack-based buffer overflow vulnerability exists in the boa formUpload() functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.
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Analysis
by VulDB Data Team • 10/20/2026
The identified vulnerability represents a critical security flaw within the web management interface of the TOTOLINK-X2000R router, specifically affecting version TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 and potentially other variants in the series. The root cause lies in the formUpload() function of the Boa web server implementation used by this device. This function is responsible for handling file uploads, a common feature in router interfaces that allows users to upload configuration files or firmware images. However, the implementation fails to adequately validate the length and structure of input data before copying it into a fixed-size stack buffer. This lack of bounds checking creates a classic stack-based buffer overflow condition. When an attacker submits a specially crafted HTTP request containing payload data exceeding the allocated buffer size, the excess data overwrites adjacent memory locations on the call stack.
This memory corruption can overwrite critical control flow data such as return addresses or function pointers stored on the stack. By carefully crafting the input to include shellcode and precise offsets for these overwritten values, an attacker can redirect the execution flow of the program. Since this vulnerability is triggered via HTTP requests processed by the web server running with elevated privileges typical of embedded device management interfaces, successful exploitation leads directly to arbitrary code execution. The attacker gains full control over the underlying operating system on the router, effectively compromising the entire network infrastructure connected through it. This level of access allows for complete data exfiltration, modification of routing tables, installation of persistent malware such as botnet clients or cryptominers, and use of the device as a pivot point to attack other internal systems.
The operational impact is severe due to the nature of home and small office networking equipment being frequently targeted by automated scanning bots. Although exploitation requires an authenticated HTTP request, many router implementations have weak default credentials or allow brute-force attacks if account lockout mechanisms are not enforced. Once authentication is bypassed or obtained through credential stuffing, the barrier to entry for this remote code execution vulnerability becomes negligible. The attacker can establish a persistent backdoor that survives reboots and may be difficult to detect using standard antivirus solutions designed for general-purpose operating systems rather than embedded Linux environments common in routers.
From a classification perspective, this flaw aligns with CWE-120: Buffer Copy without Checking Size of Input (Classic Buffer Overflow). The vulnerability is exploitable remotely over the network via HTTP, placing it within the scope of remote code execution vulnerabilities that are highly prioritized by threat intelligence platforms. In terms of MITRE ATT&CK framework mapping, this exploitation technique corresponds to T1203: Exploitation for Client Execution if targeting a client-side component or more accurately reflects server-side compromise techniques such as T1505.003: Web Shell when the attacker deploys malicious scripts via the compromised web interface, and potentially T1496: Resource Hijacking if used for cryptomining. The attack vector involves sending crafted network packets to a specific service port, typically TCP 80 or 443, leveraging protocol-specific parsing errors in the embedded Boa server.
Mitigation strategies must address both immediate remediation and long-term security posture improvements. The primary defense is applying the vendor-provided firmware update that patches the formUpload() function with proper input validation and bounds checking mechanisms such as stack canaries or non-executable stack protections if supported by the hardware architecture. If an official patch is unavailable, network-level controls should be implemented to restrict access to the router's management interface exclusively from trusted IP addresses using firewall rules. Additionally, enforcing strong, unique administrative passwords significantly raises the barrier for attackers who rely on credential guessing prior to exploiting this vulnerability. Disabling remote management features when not strictly necessary reduces the attack surface by preventing external network connections to the vulnerable web server component entirely. Regular monitoring of router logs for anomalous HTTP requests and unusual outbound traffic patterns can also aid in early detection of exploitation attempts or post-compromise activity.