CVE-2024-33214 Overview
CVE-2024-33214 is a stack-based buffer overflow in the Tenda FH1206 router running firmware version V1.2.0.8(8155)_EN. The vulnerability resides in the RouteStatic handler at ip/goform/RouteStatic, where the entrys parameter is copied into a fixed-size stack buffer without proper bounds checking. Remote, unauthenticated attackers can send a crafted HTTP request to corrupt the stack and crash the device. The flaw is classified under [CWE-120] (Buffer Copy without Checking Size of Input).
Critical Impact
Unauthenticated network attackers can trigger a denial-of-service condition on affected Tenda FH1206 routers by sending a malformed entrys parameter to the static routing endpoint.
Affected Products
- Tenda FH1206 hardware
- Tenda FH1206 firmware V1.2.0.8(8155)_EN
Discovery Timeline
- 2024-04-23 - CVE-2024-33214 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-33214
Vulnerability Analysis
The Tenda FH1206 web management interface exposes the /goform/RouteStatic endpoint, which processes static routing configuration requests. The handler reads the entrys HTTP parameter and copies its contents into a fixed-size buffer allocated on the stack. Because the handler omits length validation before the copy, attacker-controlled input can exceed the destination buffer size and overwrite adjacent stack memory, including saved return addresses.
The vulnerability is reachable over the network without authentication or user interaction. Successful exploitation produces a service crash that disrupts router availability. The Common Weakness Enumeration entry [CWE-120] classifies this as a classic buffer copy without size validation.
Consumer and small-business routers like the FH1206 frequently serve as the only network gateway for affected users. A crash of the httpd process or kernel watchdog reboot interrupts all downstream connectivity. Repeated exploitation can keep the device in a continuous reboot loop.
Root Cause
The root cause is missing input length validation in the RouteStatic form handler. The application copies the user-controlled entrys query parameter into a stack-allocated buffer using an unbounded copy routine. No check enforces that the source string length fits within the destination buffer.
Attack Vector
An attacker sends an HTTP request to ip/goform/RouteStatic with an overlong entrys parameter. The request requires no credentials and can originate from any host that can reach the router's web interface. On networks where the management interface is exposed to the WAN, the attack is reachable from the public internet. Technical analysis is documented in the Notion Resource Document.
Detection Methods for CVE-2024-33214
Indicators of Compromise
- Unexpected reboots or httpd process crashes on Tenda FH1206 devices following inbound HTTP traffic
- HTTP POST or GET requests to /goform/RouteStatic containing abnormally long entrys parameter values
- Repeated TCP connections to the router management port from a single external source
Detection Strategies
- Inspect HTTP traffic destined for the router management interface for requests targeting /goform/RouteStatic with entrys parameter lengths exceeding expected route configuration sizes
- Deploy intrusion detection rules that flag oversized query string parameters in requests to embedded device web endpoints
- Correlate router availability loss with concurrent inbound HTTP requests to the administrative interface
Monitoring Recommendations
- Log all administrative HTTP requests to network gateways and forward them to a centralized analytics platform for parameter-length anomaly review
- Monitor SNMP or syslog uptime counters on Tenda devices for unexpected restarts
- Alert on any HTTP traffic to the router management interface originating from untrusted network segments
How to Mitigate CVE-2024-33214
Immediate Actions Required
- Restrict access to the FH1206 web management interface to trusted LAN segments only and disable WAN-side administration
- Place affected routers behind upstream filtering that blocks external HTTP requests to /goform/RouteStatic
- Replace end-of-life Tenda FH1206 hardware where the vendor has not issued a firmware update addressing this flaw
Patch Information
No vendor advisory or firmware update addressing CVE-2024-33214 is referenced in the NVD entry at the time of publication. Administrators should monitor the Tenda support portal for firmware revisions beyond V1.2.0.8(8155)_EN.
Workarounds
- Disable remote management on the WAN interface through the router administration console
- Apply firewall ACLs upstream of the device to drop inbound traffic to TCP ports used by the management web service
- Segment the router management VLAN away from untrusted user networks and IoT segments
# Example upstream ACL blocking external access to the Tenda management interface
iptables -A FORWARD -p tcp -d <router_wan_ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <router_wan_ip> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
