CVE-2025-4730 Overview
CVE-2025-4730 is a buffer overflow vulnerability affecting TOTOLINK A3002R and A3002RU routers running firmware version 3.0.0-B20230809.1615. The flaw resides in the HTTP POST request handler at the /boafrm/formMapDel endpoint. Attackers can trigger the overflow by manipulating the devicemac1 argument. The vulnerability is remotely exploitable and has been publicly disclosed, increasing the risk of opportunistic exploitation against exposed devices. The weakness is classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer).
Critical Impact
Remote attackers with low privileges can corrupt memory on affected TOTOLINK routers, potentially achieving arbitrary code execution and full device compromise.
Affected Products
- TOTOLINK A3002R firmware 3.0.0-B20230809.1615
- TOTOLINK A3002RU firmware 3.0.0-B20230809.1615
- TOTOLINK A3002R and A3002RU hardware revisions running the affected firmware
Discovery Timeline
- 2025-05-16 - CVE-2025-4730 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-4730
Vulnerability Analysis
The vulnerability exists in the web management interface of the TOTOLINK A3002R and A3002RU routers. Specifically, the /boafrm/formMapDel handler within the embedded boa HTTP server processes user-supplied input from the devicemac1 POST parameter without enforcing proper length validation. When an attacker submits an overly long value for this parameter, the data overruns a fixed-size buffer in the handler's processing routine.
Exploitation requires network access to the device's web interface and a low-privilege authenticated session. Successful exploitation can corrupt adjacent memory structures, leading to denial of service or arbitrary code execution in the context of the web server process, which typically runs with elevated privileges on consumer routers.
Root Cause
The root cause is improper bounds checking on the devicemac1 argument within the formMapDel function. The handler copies attacker-controlled input into a stack or heap buffer using an unsafe string operation that does not validate the source length against the destination capacity, a classic [CWE-119] pattern common in embedded firmware written in C.
Attack Vector
The attack is launched over the network against the router's HTTP management interface. An attacker crafts a POST request to /boafrm/formMapDel containing an oversized devicemac1 value. If the management interface is exposed to the internet or reachable from a compromised LAN host, the request triggers the overflow and corrupts process memory. Public disclosure of the exploit details lowers the barrier to weaponization.
No verified proof-of-concept code is published in the NVD record. See the GitHub Temporary Storage Documentation and VulDB Vulnerability ID #309032 for technical details.
Detection Methods for CVE-2025-4730
Indicators of Compromise
- HTTP POST requests to /boafrm/formMapDel containing unusually long devicemac1 parameter values
- Unexpected reboots, crashes, or watchdog resets on TOTOLINK A3002R or A3002RU devices
- Outbound connections from the router to unknown command-and-control infrastructure following suspicious HTTP activity
Detection Strategies
- Inspect network traffic for POST requests to /boafrm/formMapDel and flag requests where devicemac1 exceeds expected MAC address length (17 characters)
- Monitor router syslog output for HTTP server crashes or restarts originating from the boa process
- Correlate authentication events on the router admin interface with subsequent abnormal POST requests targeting form handlers
Monitoring Recommendations
- Forward router logs to a centralized logging platform and alert on repeated boa crashes or restarts
- Deploy network intrusion detection signatures targeting overlong parameter values in TOTOLINK form endpoints
- Audit router admin access regularly and review which internal hosts can reach the management interface
How to Mitigate CVE-2025-4730
Immediate Actions Required
- Disable remote (WAN-side) administration on affected TOTOLINK A3002R and A3002RU devices immediately
- Restrict access to the router web interface to a dedicated management VLAN or trusted IP addresses only
- Rotate all administrative credentials on affected devices and enforce strong, unique passwords
- Inventory all TOTOLINK A3002R and A3002RU devices in the environment and identify those running firmware 3.0.0-B20230809.1615
Patch Information
At the time of NVD publication, no vendor patch is referenced for CVE-2025-4730. Administrators should monitor the Totolink Official Website for firmware updates addressing the formMapDel handler. If no patched firmware is released, consider replacing affected devices with supported hardware from a vendor with an active security update lifecycle.
Workarounds
- Place affected routers behind an upstream firewall and block external access to TCP ports used by the web management interface
- Segment the management network so only authorized administrators can reach the router admin panel
- Where feasible, disable the web management interface entirely and manage devices through a console or out-of-band channel
- Deploy network-layer filtering to drop HTTP POST requests to /boafrm/formMapDel from untrusted sources
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
