CVE-2026-8189
OS Command Injection in Wavlink NU516U1 M16U1_V240425
Publication date: 2026-05-09
Last updated on: 2026-05-09
Assigner: VulDB
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| wavlink | nu516u1 | m16u1_v240425 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-77 | The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. |
| CWE-78 | The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-8189 is a Remote Command Execution (RCE) vulnerability in the Wavlink NU516U1 device, specifically in the wzdrepeater function of the /cgi-bin/adm.cgi file.
The vulnerability occurs because the parameters wlan_bssid, sel_Automode, and sel_EncrypTyp are not properly sanitized before being used, allowing an attacker to inject operating system commands.
An attacker can exploit this remotely by sending a crafted HTTP POST request with malicious values in these parameters, which can lead to execution of arbitrary commands on the device, such as launching a shell.
How can this vulnerability impact me? :
This vulnerability allows an attacker to gain full control over the affected device remotely by executing arbitrary operating system commands.
- The attacker can run malicious commands, potentially taking over the device.
- This could lead to unauthorized access to network resources connected to the device.
- It may allow the attacker to use the device as a foothold for 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 suspicious HTTP POST requests to the /cgi-bin/adm.cgi endpoint, especially those containing the parameters wlan_bssid, sel_Automode, and sel_EncrypTyp with unusual or command-like values.
A practical detection method is to capture and inspect network traffic for POST requests targeting /cgi-bin/adm.cgi with parameters that include command injection patterns such as $(telnetd -l /bin/sh -p 8889).
- Use a network packet capture tool like tcpdump or Wireshark to filter HTTP POST requests to /cgi-bin/adm.cgi.
- Example tcpdump command: tcpdump -A -s 0 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)' | grep '/cgi-bin/adm.cgi'
- Use curl or similar tools to test if the device is vulnerable by sending crafted POST requests with malicious parameters.
- Example curl command to test: curl -X POST http://<target-ip>/cgi-bin/adm.cgi -d 'wlan_bssid=xx&sel_Automode=$(telnetd -l /bin/sh -p 8889)&sel_EncrypTyp=yy'
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting access to the vulnerable /cgi-bin/adm.cgi endpoint to trusted networks only, such as by using firewall rules or network segmentation.
Additionally, disable or restrict remote management interfaces if not needed, and monitor logs for suspicious activity related to the vulnerable parameters.
If possible, apply any available firmware updates or patches provided by the vendor to fix the command injection vulnerability.
As a temporary workaround, consider disabling the wzdrepeater function or the affected CGI script until a patch is applied.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows remote command execution on the affected device, which can lead to unauthorized access and control over the system.
Such unauthorized access could result in exposure or manipulation of sensitive data, potentially violating data protection regulations like GDPR or HIPAA.
Therefore, this vulnerability could negatively impact compliance with common standards and regulations that require protection of data confidentiality, integrity, and availability.