CVE-2026-5042
Stack-Based Buffer Overflow in Belkin F9K1122 Parameter Handler
Publication date: 2026-03-29
Last updated on: 2026-03-30
Assigner: VulDB
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| belkin | f9k1122_firmware | 1.00.33 |
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
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify how the vulnerability in Belkin F9K1122 affects compliance with common standards and regulations such as GDPR or HIPAA.
Can you explain this vulnerability to me?
This vulnerability is a stack-based buffer overflow found in the Belkin F9K1122 router firmware version 1.00.33. It occurs in the web interface function formCrossBandSwitch, which processes a user-supplied parameter called "webpage." The function copies this parameter into a fixed-size buffer without checking its length, allowing an attacker to overflow the buffer by sending an excessively long "webpage" value via a POST request to the /goform/formCrossBandSwitch endpoint.
Because there is no bounds checking, the overflow can overwrite adjacent memory, potentially leading to denial of service or remote code execution on the device.
How can this vulnerability impact me? :
Exploiting this vulnerability can allow an attacker to remotely execute arbitrary code or cause a denial of service on the affected Belkin F9K1122 router. This means the attacker could take control of the device, disrupt its normal operation, or use it as a foothold to launch further attacks within the network.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring for POST requests sent to the /goform/formCrossBandSwitch endpoint containing an excessively long "webpage" parameter. Such requests may indicate attempts to exploit the stack-based buffer overflow.
A practical detection method is to capture and analyze HTTP traffic targeting the Belkin F9K1122 router, specifically looking for unusually large payloads in the "webpage" parameter within POST requests.
Example commands to detect potential exploitation attempts include using network packet capture tools like tcpdump or tshark:
- tcpdump -i <interface> -A -s 0 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)' | grep -i 'POST /goform/formCrossBandSwitch'
- tshark -i <interface> -Y 'http.request.method == "POST" and http.request.uri contains "/goform/formCrossBandSwitch"' -T fields -e http.file_data
Inspect the captured POST data for the "webpage" parameter and check if its length exceeds normal expected sizes, which could indicate an exploit attempt.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting access to the vulnerable router's web interface to trusted networks only, such as by using firewall rules or network segmentation.
Disabling remote management or remote access to the router's web interface can prevent attackers from launching the exploit remotely.
Monitor network traffic for suspicious POST requests targeting the /goform/formCrossBandSwitch endpoint with large "webpage" parameters and block or alert on such traffic.
Since the vendor has not responded with a patch, consider replacing or upgrading the device firmware if a fixed version becomes available or using alternative hardware until a fix is released.