CVE-2026-3974
Stack-Based Buffer Overflow in Tenda W3 HTTP Handler Allows Remote Attack
Publication date: 2026-03-12
Last updated on: 2026-04-02
Assigner: VulDB
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| tenda | w3_firmware | 1.0.0.3(2204) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-119 | The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. |
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
| CWE-121 | A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-3974 is a critical stack-based buffer overflow vulnerability found in the Tenda W3 router, version 1.0.0.3(2204).
The flaw exists in the HTTP handler component, specifically within the function formexeCommand located at the endpoint /goform/exeCommand.
The vulnerability arises from improper handling of the cmdinput argument, where manipulation with crafted input leads to a stack-based overflow condition.
This overflow can be triggered remotely without authentication, making exploitation straightforward and accessible to attackers.
How can this vulnerability impact me? :
Exploitation of this vulnerability can impact the confidentiality, integrity, and availability of the affected device.
An attacker can send a specially crafted POST request with an excessively long payload in the cmdinput parameter, causing a stack-based buffer overflow.
This can lead to arbitrary code execution or denial of service by crashing the HTTP daemon process.
Since the attack can be performed remotely without authentication, it poses a significant security risk.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
[{'type': 'paragraph', 'content': 'This vulnerability can be detected by monitoring HTTP POST requests sent to the /goform/exeCommand endpoint on the Tenda W3 router, specifically looking for unusually long or crafted payloads in the cmdinput parameter.'}, {'type': 'paragraph', 'content': 'A practical detection method involves sending a test POST request with a large string in the cmdinput field to check if the device responds abnormally or crashes, indicating the presence of the vulnerability.'}, {'type': 'paragraph', 'content': 'Example command using curl to test the vulnerability:'}, {'type': 'list_item', 'content': 'curl -X POST http://[router_ip]/goform/exeCommand -d "cmdinput=$(python3 -c \'print("a"*1000)\')"'}, {'type': 'paragraph', 'content': 'If the router crashes, becomes unresponsive, or exhibits abnormal behavior after this request, it is likely vulnerable.'}] [2, 3]
What immediate steps should I take to mitigate this vulnerability?
There are no known countermeasures or mitigations available for this vulnerability.
The recommended immediate step is to replace the affected Tenda W3 router with an alternative device that is not vulnerable.
Additionally, restricting remote HTTP access to the router and monitoring network traffic for suspicious POST requests to /goform/exeCommand can help reduce exposure.