CVE-2026-93741 in A3002MU
Summary
by MITRE • 09/19/2026
A security flaw has been discovered in Totolink A3002MU Hh-B20211125.1046. Affected by this vulnerability is the function formWlWds of the file /boafrm/formWlWds. The manipulation of the argument submit-url results in buffer overflow. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 09/19/2026
The vulnerability identified in Totolink A3002MU firmware version Hh-B20211125.1046 represents a critical security flaw located within the web management interface of the device, specifically affecting the formWlWds function found in the /boafrm/formWlWds file. This component is part of the embedded Boa web server commonly used in consumer-grade networking equipment to handle administrative configuration requests. The core technical issue stems from a buffer overflow condition triggered by improper validation and bounds checking when processing the submit-url argument passed during HTTP POST requests. When an attacker supplies a carefully crafted, excessively long string as the value for this parameter, it exceeds the allocated memory buffer size defined within the application logic. This discrepancy causes data to spill over into adjacent memory regions, corrupting stack or heap structures that are critical for normal program execution flow.
From a technical perspective, this flaw is classified under CWE-120, which denotes Buffer Copy without Checking Size of Input, and often falls under the broader category of CWE-787 if it leads to out-of-bounds write operations. The absence of rigorous input sanitization allows external actors to manipulate memory layout directly through network requests. Because this function is exposed via the web interface, the vulnerability is remotely exploitable without requiring prior authentication in many default configurations or potentially even with limited privileges depending on how the specific firmware version handles session tokens for administrative endpoints. This remote accessibility significantly lowers the barrier to entry for attackers seeking to compromise the device infrastructure.
The operational impact of successfully exploiting this buffer overflow can be severe, ranging from denial of service to arbitrary code execution. By overwriting return addresses or function pointers in memory, an attacker can redirect the program's control flow to execute malicious shellcode injected via the same request payload. This capability effectively grants full remote command and control access to the vulnerable router, allowing the compromise of local network integrity, interception of traffic, pivoting into internal networks, or enlistment of the device into a botnet for distributed denial-of-service attacks. The fact that public exploits have been released further amplifies this risk, as automated scanning tools and opportunistic attackers can rapidly identify and exploit vulnerable instances across the internet without needing to develop custom attack vectors from scratch.
Mitigation strategies must prioritize immediate remediation through firmware updates provided by Totolink if available for this specific build. In cases where patches are not immediately accessible or applicable, network-level controls should be implemented to restrict access to the device's management interface. This includes disabling remote administration features entirely and ensuring that administrative ports are only reachable from trusted internal IP addresses via firewall rules. Additionally, deploying intrusion detection systems with signatures capable of detecting buffer overflow patterns in HTTP traffic can provide an additional layer of defense by blocking malicious payloads before they reach the vulnerable application logic. Continuous monitoring for unusual outbound connections or configuration changes is also recommended to detect potential compromise early.