CVE-2026-13582 Overview
CVE-2026-13582 is a buffer overflow vulnerability in the Edimax EW-7478APC wireless access point running firmware version 1.04. The flaw resides in the formUSBAccount function within /goform/formUSBAccount, a POST request handler exposed by the device's web management interface. Attackers can trigger the overflow by manipulating the UserName or Password arguments in a crafted POST request. The exploit has been published, and the vendor did not respond to disclosure attempts. Because the attack is executed over the network against a router-class device, exploitation can compromise the confidentiality, integrity, and availability of the affected system.
Critical Impact
Remote attackers with low-level authentication can overflow a buffer in the formUSBAccount handler, corrupting memory on the Edimax EW-7478APC and potentially executing arbitrary code on the device.
Affected Products
- Edimax EW-7478APC wireless access point
- Firmware version 1.04
- formUSBAccount POST request handler in /goform/formUSBAccount
Discovery Timeline
- 2026-06-29 - CVE-2026-13582 published to NVD
- 2026-06-29 - Last updated in NVD database
Technical Details for CVE-2026-13582
Vulnerability Analysis
The vulnerability is a classic buffer overflow classified as [CWE-119], improper restriction of operations within the bounds of a memory buffer. The formUSBAccount handler processes POST requests submitted through the device's web administration interface. When the handler copies the UserName and Password fields into fixed-size buffers, it does not enforce length limits on the attacker-supplied data. Oversized values write past the destination buffer boundaries and corrupt adjacent memory. On embedded devices such as the EW-7478APC, this class of flaw commonly leads to arbitrary code execution because the firmware typically lacks modern mitigations like address space layout randomization and stack canaries.
Root Cause
The root cause is the absence of bounds checking when the formUSBAccount function processes the UserName and Password parameters. The handler trusts client-supplied input lengths and copies the data into stack or heap buffers without validating that the source length is smaller than the destination capacity. This missing validation allows adjacent memory, saved return addresses, or function pointers to be overwritten.
Attack Vector
Exploitation is performed remotely over the network. An authenticated attacker with low privileges sends a crafted HTTP POST request to /goform/formUSBAccount containing oversized UserName or Password values. Because the exploit has been publicly disclosed, opportunistic scanning and weaponization are feasible. Successful exploitation impacts confidentiality, integrity, and availability of the access point, and can be used to pivot into internal networks the device services.
No verified proof-of-concept code is reproduced here. Technical details are documented in the published advisory referenced in the Notion Document on EDIMAX and the VulDB CVE-2026-13582 entry.
Detection Methods for CVE-2026-13582
Indicators of Compromise
- HTTP POST requests targeting /goform/formUSBAccount with abnormally long UserName or Password field values.
- Unexpected reboots, service crashes, or watchdog resets on the EW-7478APC coinciding with web management traffic.
- New or unknown outbound connections originating from the access point's management IP address.
Detection Strategies
- Deploy network intrusion detection signatures that match POST requests to /goform/formUSBAccount exceeding expected form field sizes.
- Inspect web application firewall or reverse proxy logs for requests to the affected endpoint containing binary or non-printable characters.
- Correlate management-interface access attempts with device availability events to identify probing or exploitation.
Monitoring Recommendations
- Log and alert on all administrative HTTP traffic to the EW-7478APC management interface, restricting sources to known operator subnets.
- Baseline device CPU, memory, and network behavior to identify anomalies indicative of post-exploitation activity.
- Monitor egress traffic from the access point for command-and-control indicators and unexpected protocols.
How to Mitigate CVE-2026-13582
Immediate Actions Required
- Remove the EW-7478APC web management interface from untrusted networks and restrict access to a dedicated management VLAN.
- Change any shared or default administrative credentials to limit which users can reach the authenticated formUSBAccount endpoint.
- Place the device behind a firewall that blocks inbound HTTP and HTTPS to the management interface from user or guest networks.
Patch Information
The vendor was contacted about this disclosure but did not respond, and no vendor patch or advisory is currently available. Operators should track the VulDB Vulnerability #374588 entry for updates and confirm any future firmware releases from Edimax before applying them.
Workarounds
- Disable the USB account configuration feature if it is not required for operations.
- Replace the affected access point with a supported model if the vendor does not issue firmware providing bounds checks on formUSBAccount input.
- Terminate management sessions from unauthorized sources using upstream access control lists on switches or routers.
# Example: restrict access to the Edimax management interface with iptables
# Allow only the admin workstation 10.10.10.5 to reach the device at 192.168.1.10
iptables -A FORWARD -s 10.10.10.5 -d 192.168.1.10 -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d 192.168.1.10 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.168.1.10 -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
