CVE-2025-15471: Trendnet TEW-713RE Firmware RCE Flaw

CVE-2025-15471 Overview

CVE-2025-15471 is an operating system command injection vulnerability in the TRENDnet TEW-713RE wireless range extender running firmware version 1.02. The flaw resides in an unknown function of the /goformX/formFSrvX endpoint, where unsanitized input passed through the SZCMD parameter is executed as a shell command. An unauthenticated remote attacker can reach the endpoint over the network and execute arbitrary commands on the device. The exploit is publicly disclosed. TRENDnet has confirmed that the TEW-713RE has been discontinued and reached end-of-life on October 23, 2020, and no patch will be issued.

Critical Impact

Unauthenticated remote command execution on an end-of-life device with no vendor patch available, enabling full compromise of the network appliance.

Affected Products

• TRENDnet TEW-713RE hardware (all units running affected firmware)
• TRENDnet TEW-713RE firmware version 1.0.2
• Status: End-of-life as of October 23, 2020 (no fix forthcoming)

Discovery Timeline

• 2026-01-07 - CVE-2025-15471 published to NVD
• 2026-03-18 - Last updated in NVD database

Technical Details for CVE-2025-15471

Vulnerability Analysis

The vulnerability is classified as OS Command Injection [CWE-77]. The affected endpoint /goformX/formFSrvX processes a request parameter named SZCMD and incorporates its value into a shell command invocation without sanitization. Because the handler runs in the embedded web server context of the range extender, executed commands inherit the privileges of that service, which on TRENDnet consumer devices is typically root.

The attack requires no authentication, no user interaction, and only network reachability to the device management interface. Successful exploitation grants attackers the ability to drop persistent implants, pivot into the LAN, intercept traffic, or recruit the device into a botnet.

Root Cause

The root cause is the direct concatenation of attacker-controlled input from the SZCMD argument into an OS-level command, most commonly through system(), popen(), or similar shell-invoking functions in the formFSrvX handler. The handler does not validate, allowlist, or shell-escape metacharacters such as ;, |, &, or backticks.

Attack Vector

Exploitation occurs over the network against the device's HTTP management interface. An attacker submits a crafted request to /goformX/formFSrvX with shell metacharacters appended to the SZCMD parameter. The injected payload executes alongside the intended command. Public technical analysis of the flaw is available in the Notion Command Injection Analysis writeup and the VulDB entry #339721.

No verified proof-of-concept code is reproduced here. The vulnerability mechanism is described in prose; refer to the linked external advisories for request-level technical details.

Detection Methods for CVE-2025-15471

Indicators of Compromise

• HTTP requests to the URI path /goformX/formFSrvX containing a SZCMD parameter with shell metacharacters such as ;, |, &&, or backticks.
• Outbound connections originating from the TEW-713RE management IP to unfamiliar hosts, particularly on ports associated with reverse shells (4444, 1337) or downloader infrastructure.
• Unexpected processes such as wget, tftp, nc, or busybox invocations correlated with management-plane HTTP activity.

Detection Strategies

• Inspect web server and reverse-proxy logs that front the device for POST or GET requests to formFSrvX with non-alphanumeric content in SZCMD.
• Deploy network IDS signatures (Snort/Suricata) that match the URI pattern combined with command-injection metacharacters in the request body.
• Baseline NetFlow from administrative VLANs and alert on TEW-713RE devices initiating outbound sessions, which they should rarely do.

Monitoring Recommendations

• Restrict and continuously monitor the management interfaces of consumer-grade extenders; treat any inbound WAN-side traffic to these devices as suspicious.
• Forward DHCP, DNS, and firewall logs to a centralized analytics platform to identify devices acting as pivot points after compromise.
• Add the TEW-713RE asset class to an end-of-life inventory watchlist and alert on any new device of this model appearing on the network.

How to Mitigate CVE-2025-15471

Immediate Actions Required

• Remove TRENDnet TEW-713RE devices from production networks; TRENDnet has confirmed the product is end-of-life and will not receive a patch.
• If immediate removal is not possible, isolate the device on a dedicated VLAN with no inbound access from untrusted networks and no outbound internet egress.
• Disable remote management features and ensure the web administration interface is unreachable from the WAN side.
• Replace affected hardware with a currently supported wireless extender that receives security updates.

Patch Information

No patch is available. TRENDnet's published position is that the TEW-713RE has been discontinued and end-of-life since October 23, 2020, and that the vendor will not be releasing fixes. Customers are being notified through the product support page on the vendor website.

Workarounds

• Block all inbound traffic to /goformX/formFSrvX at an upstream firewall or reverse proxy until the device is decommissioned.
• Restrict access to the device's web UI to a single management workstation by source-IP allowlisting.
• Disable Wi-Fi and unplug the device when not actively in use to reduce exposure window.

# Configuration example: block HTTP access to the vulnerable endpoint at an upstream firewall (iptables)
iptables -A FORWARD -p tcp -d <TEW-713RE-IP> --dport 80 -m string \
  --algo bm --string "/goformX/formFSrvX" -j DROP
iptables -A FORWARD -p tcp -d <TEW-713RE-IP> --dport 80 \
  ! -s <ADMIN-WORKSTATION-IP> -j DROP