CVE-2024-51311 Overview
CVE-2024-51311 is a stack overflow vulnerability in the Tenda TX9 router running firmware version V22.03.02.05. The flaw resides in the sub_4418CC function that handles requests to the /goform/SetNetControlList endpoint. An unauthenticated remote attacker can send a crafted HTTP request to trigger memory corruption on the router's stack. Successful exploitation can lead to denial of service or arbitrary code execution on the affected device. The vulnerability is classified under CWE-121: Stack-based Buffer Overflow.
Critical Impact
Unauthenticated network attackers can trigger a stack-based buffer overflow through the /goform/SetNetControlList endpoint, potentially achieving remote code execution on affected Tenda TX9 routers.
Affected Products
- Tenda TX9 router
- Firmware version V22.03.02.05
- Web management interface exposing /goform/SetNetControlList
Discovery Timeline
- 2026-07-20 - CVE-2024-51311 published to NVD
- 2026-07-21 - Last updated in NVD database
Technical Details for CVE-2024-51311
Vulnerability Analysis
The vulnerability exists in the sub_4418CC function within the Tenda TX9 firmware. This function processes HTTP POST parameters submitted to the /goform/SetNetControlList endpoint of the router's built-in web server. The function copies attacker-controlled input into a fixed-size stack buffer without validating the input length. When the supplied data exceeds the buffer size, adjacent stack memory is overwritten, including saved return addresses and register values.
Because the affected endpoint is reachable over the network without authentication, an attacker on the same network segment or one able to reach the router's management interface can trigger the flaw. Embedded MIPS-based devices such as the TX9 typically lack modern exploit mitigations like Address Space Layout Randomization (ASLR) and stack canaries. This absence makes reliable exploitation for remote code execution feasible.
Root Cause
The root cause is missing bounds checking on user-supplied input inside sub_4418CC before it is copied into a stack buffer. The function trusts request data from /goform/SetNetControlList and performs an unsafe copy operation. This is a classic instance of [CWE-121] where input length is not validated against the destination buffer capacity.
Attack Vector
Exploitation requires network access to the router's HTTP management interface. The attacker sends a crafted POST request to /goform/SetNetControlList containing an overly long parameter value. Processing that request drives the vulnerable function to overwrite the stack. Refer to the Gitee IoT Vulnerability Report for endpoint details and reproduction notes.
No verified public exploit code is available. Technical analysis is described in the referenced advisory without reproducible synthetic code here.
Detection Methods for CVE-2024-51311
Indicators of Compromise
- Unexpected HTTP POST requests to /goform/SetNetControlList from untrusted hosts on the LAN.
- Router reboots, watchdog resets, or crash loops shortly after receiving malformed management requests.
- Configuration changes to network control lists that were not initiated by an administrator.
Detection Strategies
- Inspect HTTP traffic destined for the router management interface for POST bodies with abnormally long parameter values targeting /goform/ endpoints.
- Deploy network intrusion detection signatures that flag requests to /goform/SetNetControlList containing oversized fields.
- Correlate router availability alerts with preceding management-plane HTTP traffic to identify potential exploitation attempts.
Monitoring Recommendations
- Forward router syslog and management-plane access logs to a centralized logging platform for retention and analysis.
- Monitor for repeated connection attempts to the router's HTTP administration port from unauthorized client addresses.
- Alert on any external or wireless-guest source communicating with the router administration interface.
How to Mitigate CVE-2024-51311
Immediate Actions Required
- Restrict access to the router's web management interface to trusted management VLANs or specific administrator hosts.
- Disable remote (WAN-side) administration on the Tenda TX9 if it is currently enabled.
- Isolate untrusted devices and guest networks from the router management interface using firewall rules or network segmentation.
Patch Information
At the time of publication, no vendor patch is referenced in the NVD entry for CVE-2024-51311. Check the Tenda Firmware Download Page for updated firmware releases addressing this issue, and apply any published update as soon as it is available.
Workarounds
- Block inbound access to the router's HTTP administration port from the WAN interface at the perimeter.
- Change default administrator credentials and enforce strong passwords to reduce risk from adjacent-network attackers who reach the interface.
- Consider replacing the device with a supported model if a fixed firmware version is not made available by the vendor.
# Example: restrict management interface access to a single admin host using iptables on an upstream gateway
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -s <admin_host_ip> -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
