CVE-2026-10136 in Totolink
Summary
by MITRE • 10/21/2026
A heap-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 • 10/21/2026
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. This issue is classified as a heap-based buffer overflow located within the formUpload() function of the boa web server implementation. The vulnerability arises from insufficient bounds checking when processing file upload requests, allowing an attacker to write data beyond the allocated memory boundaries on the heap. Such memory corruption issues are fundamentally categorized under CWE-122, which denotes a heap-based buffer overflow where input validation fails to restrict the size of incoming data relative to the destination buffer's capacity.
The operational impact of this vulnerability is severe due to its potential for arbitrary code execution. By crafting a malicious HTTP request with specifically designed payload parameters, an attacker can overwrite adjacent memory structures on the heap, such as function pointers or object metadata. This manipulation allows the attacker to redirect program flow to execute shellcode injected into the buffer, thereby gaining full control over the router's operating system. Since this vulnerability requires authentication to trigger, it is typically exploited by attackers who have already obtained valid credentials through phishing, brute-force attacks on weak default passwords, or credential stuffing campaigns. This aligns with MITRE ATT&CK technique T1078, which covers Valid Accounts, indicating that the exploitation chain often begins with unauthorized access to legitimate user accounts before leveraging this memory corruption flaw for privilege escalation and remote code execution.
The presence of such a vulnerability in embedded networking devices highlights significant deficiencies in secure coding practices during firmware development. The boa web server is commonly used in routers due to its lightweight nature, but it requires rigorous input sanitization and buffer management to prevent exploitation. In this specific instance, the lack of proper length validation for uploaded form data creates an exploitable condition that can be triggered remotely over HTTP once authentication is bypassed or obtained. This underscores the risk associated with consumer-grade networking equipment where security features are often secondary to functionality and cost constraints.
Mitigation strategies must focus on both immediate remediation and long-term defensive posture improvements. The primary solution involves applying vendor-provided firmware updates that patch the formUpload() function by implementing strict buffer size checks and using safe string handling functions that prevent overflow conditions. If an update is not immediately available, network administrators should enforce strong, unique passwords for all administrative accounts to reduce the likelihood of credential compromise. Additionally, restricting access to the router's web management interface via IP whitelisting or disabling remote HTTP/HTTPS administration can significantly lower the attack surface. It is also advisable to disable unnecessary services and features on the device to minimize potential entry points. Regular vulnerability scanning and monitoring for anomalous network traffic patterns related to file uploads can aid in early detection of exploitation attempts before full system compromise occurs.