CVE-2026-13561: Edimax EW-7478APC RCE Vulnerability

CVE-2026-13561 Overview

CVE-2026-13561 is an operating system command injection vulnerability [CWE-77] affecting Edimax EW-7478APC firmware version 1.04. The flaw resides in the formiNICbasic function reached through the /goform/formiNICbasic endpoint in the POST request handler. Attackers manipulate the rootAPmac parameter to inject arbitrary shell commands. The attack requires network access and low-privilege authentication. Public exploit details are available, and the vendor did not respond to disclosure attempts.

Critical Impact
Authenticated remote attackers can inject operating system commands into the rootAPmac parameter of /goform/formiNICbasic, leading to arbitrary command execution on the device.

Affected Products

Edimax EW-7478APC firmware version 1.04
Component: POST Request Handler
Vulnerable function: formiNICbasic at /goform/formiNICbasic

Discovery Timeline

2026-06-29 - CVE-2026-13561 published to NVD
2026-06-29 - Last updated in NVD database

Technical Details for CVE-2026-13561

Vulnerability Analysis

The Edimax EW-7478APC wireless access point exposes a web administration interface that routes POST requests to internal handler functions. The formiNICbasic handler processes network interface card configuration submitted via /goform/formiNICbasic. One of the parameters, rootAPmac, is passed to a system shell without proper sanitization or argument escaping. This allows an attacker to append shell metacharacters and secondary commands to the intended MAC address value.

Exploitation requires network reachability to the device management interface and a valid low-privilege session. The vulnerability is classified under [CWE-77] Improper Neutralization of Special Elements Used in a Command. The EPSS probability is 1.158% at the 63.205 percentile, indicating measurable exploitation interest given the public exploit and unresponsive vendor.

Root Cause

The root cause is missing input validation on the rootAPmac parameter before it reaches an operating system command invocation. The handler concatenates attacker-controlled input into a shell command string rather than passing it as a bounded argument or validating it against a MAC address regular expression. Shell metacharacters such as ;, |, &, and backticks pass through unfiltered.

Attack Vector

An authenticated attacker submits a crafted POST request to /goform/formiNICbasic with a malicious rootAPmac value. The injected payload executes with the privileges of the web server process, which on embedded Edimax devices typically runs as root. Public disclosure of exploitation details is hosted on external documentation, referenced in the Notion Documentation and the VulDB CVE-2026-13561 entry.

No verified proof-of-concept code is reproduced here. Refer to the linked advisories for exploitation specifics.

Detection Methods for CVE-2026-13561

Indicators of Compromise

POST requests to /goform/formiNICbasic containing shell metacharacters such as ;, |, &, $(, or backticks in the rootAPmac parameter
Unexpected outbound connections initiated from the access point management IP address
New or unknown processes running on the device that are not part of standard firmware operation
Log entries showing successful configuration changes immediately followed by anomalous system activity

Detection Strategies

Inspect HTTP request bodies destined for /goform/formiNICbasic for values that do not match the standard MAC address format [0-9A-Fa-f:]{17}
Deploy network intrusion detection signatures that flag command injection patterns in rootAPmac and adjacent POST parameters
Baseline management-plane traffic to the access point and alert on deviations in request volume or client source

Monitoring Recommendations

Forward device syslog and web server access logs to a central collector for retention and correlation
Monitor for administrative logins from unexpected source addresses or outside change windows
Track configuration changes to the formiNICbasic interface and correlate with authenticated session activity

How to Mitigate CVE-2026-13561

Immediate Actions Required

Restrict access to the device management interface to trusted administrative networks using firewall or VLAN segmentation
Change default and shared administrative credentials to limit the pool of accounts capable of reaching the vulnerable endpoint
Audit existing sessions and administrative accounts for signs of unauthorized configuration changes
Consider replacing the affected model if it is deployed in exposed or high-value network segments, given the lack of vendor response

Patch Information

No vendor patch is available. According to the CVE record, Edimax was contacted early about this disclosure but did not respond. Consult the VulDB Vulnerability Report #374569 for ongoing status updates.

Workarounds

Disable remote management on the WAN interface and permit configuration only from a dedicated management VLAN
Place the access point behind a reverse proxy or web application firewall that enforces strict rootAPmac input validation against a MAC address pattern
Remove low-privilege accounts that do not require access to the network interface configuration screens
Plan migration to a supported wireless access point from a vendor with an active security response process

bash

# Example firewall restriction limiting management access to a trusted subnet
iptables -A INPUT -p tcp --dport 80 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP