CVE-2025-12214 Overview
CVE-2025-12214 is a stack-based buffer overflow vulnerability in the Tenda O3 router running firmware version 1.0.0.10(2478). The flaw resides in the SetValue and GetValue functions of the /goform/sysAutoReboot endpoint. Attackers can trigger the overflow by manipulating the enable parameter sent to this endpoint. The vulnerability is remotely exploitable and a public exploit is available, increasing the likelihood of opportunistic attacks against exposed devices. The weakness is categorized under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer).
Critical Impact
Remote attackers with low privileges can corrupt stack memory on Tenda O3 devices, leading to denial of service or potential arbitrary code execution on the embedded device.
Affected Products
- Tenda O3 hardware (version 2.0)
- Tenda O3 firmware 1.0.0.10(2478)
- Web management interface endpoint /goform/sysAutoReboot
Discovery Timeline
- 2025-10-27 - CVE-2025-12214 published to NVD
- 2026-02-24 - Last updated in NVD database
Technical Details for CVE-2025-12214
Vulnerability Analysis
The vulnerability exists in the HTTP request handler for the /goform/sysAutoReboot endpoint exposed by the Tenda O3 router's web management interface. Both the SetValue and GetValue functions process the enable parameter without enforcing proper length validation before copying it into a fixed-size stack buffer. When an attacker submits an oversized enable value, the copy operation overruns the buffer boundary and corrupts adjacent stack frame data, including saved return addresses.
On MIPS-based embedded routers like the Tenda O3, controlled overwrite of the return address can redirect execution flow. Combined with predictable memory layouts and absent or weak exploit mitigations common to consumer IoT firmware, this primitive can enable arbitrary code execution as the web server process, which typically runs as root.
Root Cause
The root cause is missing bounds checking in the SetValue and GetValue handlers within /goform/sysAutoReboot. The handler trusts the attacker-controlled length of the enable argument and copies it into a stack buffer using an unsafe string operation. This is a classic instance of [CWE-119], improper restriction of operations within memory buffer bounds.
Attack Vector
The attack is delivered over the network via crafted HTTP requests to the router's management interface. An attacker with at least low-privileged access to the web interface submits a request to /goform/sysAutoReboot containing an enable parameter of excessive length. Exploitation requires no user interaction. Devices exposing their management interface to untrusted networks face the highest risk. Technical reproduction details are available in the public GitHub PoC Repository and the VulDB entry #329884.
Detection Methods for CVE-2025-12214
Indicators of Compromise
- HTTP POST or GET requests to /goform/sysAutoReboot containing abnormally long enable parameter values.
- Unexpected reboots, crashes, or watchdog resets of the Tenda O3 device coinciding with management interface traffic.
- Outbound connections from the router to unfamiliar hosts following suspicious management interface requests.
Detection Strategies
- Inspect HTTP traffic destined for the router management interface and flag requests where enable exceeds expected byte lengths.
- Correlate router crash or reboot events with preceding inbound HTTP traffic to /goform/ endpoints.
- Use network intrusion detection signatures to alert on requests targeting /goform/sysAutoReboot from unauthorized source networks.
Monitoring Recommendations
- Restrict and log access to the router's web management interface, capturing source IP, URI, and parameter lengths.
- Monitor for repeated authentication attempts followed by malformed POST requests to goform URIs.
- Track outbound traffic from the router to detect post-exploitation command-and-control activity.
How to Mitigate CVE-2025-12214
Immediate Actions Required
- Disable remote (WAN-side) administration on affected Tenda O3 devices immediately.
- Restrict LAN-side access to the management interface to a small set of trusted administrative hosts.
- Change default and shared credentials to reduce the risk of low-privileged attackers reaching the vulnerable endpoint.
- Inventory all Tenda O3 deployments running firmware 1.0.0.10(2478) and prioritize replacement or isolation.
Patch Information
No vendor patch has been published in the referenced advisories at the time of CVE publication. Operators should monitor the Tenda Official Website for firmware updates addressing the sysAutoReboot handler. Until a fix is available, treat affected devices as exposed and apply compensating network controls.
Workarounds
- Place affected routers behind a separate firewall and block inbound HTTP/HTTPS to the management interface from untrusted networks.
- Segment IoT and management VLANs so the router web UI is not reachable from general user networks.
- Replace end-of-life or unpatched Tenda O3 devices with hardware that receives current security maintenance.
# Example: block external access to the router management interface
# Apply on an upstream firewall (adjust ROUTER_IP and MGMT_PORT as needed)
iptables -A FORWARD -p tcp -d <ROUTER_IP> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <ROUTER_IP> --dport 443 -j DROP
# Allow only a trusted admin host
iptables -I FORWARD -p tcp -s <ADMIN_HOST_IP> -d <ROUTER_IP> --dport 80 -j ACCEPT
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
