CVE-2024-30628: Tenda FH1205 Buffer Overflow Vulnerability

CVE-2024-30628 Overview

CVE-2024-30628 is a critical stack overflow vulnerability affecting Tenda FH1205 wireless routers running firmware version 2.0.0.7(775). The vulnerability exists in the page parameter handling within the fromAddressNat function, allowing attackers to overwrite stack memory and potentially achieve remote code execution on affected devices.

Critical Impact

This stack overflow vulnerability enables unauthenticated remote attackers to potentially execute arbitrary code or crash affected Tenda FH1205 routers, compromising network security and device availability.

Affected Products

• Tenda FH1205 Firmware version 2.0.0.7(775)
• Tenda FH1205 Hardware

Discovery Timeline

• 2024-03-29 - CVE-2024-30628 published to NVD
• 2025-03-14 - Last updated in NVD database

Technical Details for CVE-2024-30628

Vulnerability Analysis

This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow), a memory corruption flaw that occurs when a program writes data beyond the boundary of a fixed-length buffer allocated on the stack. In the context of the Tenda FH1205 router, the fromAddressNat function fails to properly validate the length of user-supplied input through the page parameter before copying it to a stack buffer.

The vulnerability is particularly severe because it can be exploited remotely without any authentication requirements. An attacker with network access to the device's web management interface can craft malicious requests containing oversized input for the page parameter, causing stack memory corruption.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the fromAddressNat function. The function accepts user-controlled data via the page parameter but does not perform adequate bounds checking before copying this data into a fixed-size stack buffer. This oversight allows an attacker to supply input that exceeds the buffer's allocated size, overwriting adjacent stack memory including potentially the return address.

Attack Vector

The attack can be executed remotely over the network without requiring any authentication or user interaction. An attacker would need network access to the Tenda FH1205 router's web management interface to exploit this vulnerability.

The exploitation process involves sending specially crafted HTTP requests to the router's web interface that include an excessively long string in the page parameter when invoking the fromAddressNat function. This causes the stack buffer to overflow, potentially allowing an attacker to:

1. Overwrite the saved return address on the stack
2. Redirect program execution to attacker-controlled code
3. Cause a denial of service by crashing the device

For detailed technical information about this vulnerability, refer to the GitHub IoT Vulnerability Documentation.

Detection Methods for CVE-2024-30628

Indicators of Compromise

• Unexpected router reboots or crashes without administrator intervention
• Anomalous HTTP requests to the router's web management interface containing unusually long parameter values
• Network traffic patterns showing repeated connection attempts to the router's management port
• Unusual firmware modifications or configuration changes on the device

Detection Strategies

• Monitor network traffic for HTTP requests to the Tenda FH1205 web interface with abnormally long page parameter values
• Implement intrusion detection rules to flag requests targeting the fromAddressNat endpoint with oversized payloads
• Deploy network segmentation to isolate IoT devices and enable granular traffic monitoring
• Review router logs for authentication failures or unusual access patterns

Monitoring Recommendations

• Enable logging on all network perimeter devices to capture traffic to and from IoT devices
• Implement network-based anomaly detection to identify buffer overflow exploitation attempts
• Establish baseline traffic patterns for IoT devices to quickly identify deviations
• Consider placing IoT devices on isolated VLANs with strict access controls

How to Mitigate CVE-2024-30628

Immediate Actions Required

• Restrict network access to the Tenda FH1205 web management interface to trusted IP addresses only
• Disable remote management if not required for operations
• Place the affected router behind a firewall with strict ingress filtering
• Consider replacing the vulnerable device with a supported alternative if no patch is available

Patch Information

No vendor patch information is currently available for this vulnerability. Users should monitor Tenda's official support channels for firmware updates addressing CVE-2024-30628. Given the critical severity of this vulnerability, organizations should prioritize network isolation measures and consider device replacement if patches are not forthcoming.

Workarounds

• Disable the web management interface entirely if not operationally required
• Implement network access control lists (ACLs) to restrict access to the router's management interface
• Use a VPN or jump host for administrative access rather than exposing the management interface
• Deploy a web application firewall (WAF) in front of the device to filter malicious requests

# Example iptables rules to restrict management interface access
# Replace 192.168.1.100 with your admin workstation IP
# Replace 192.168.1.1 with your router IP

iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 443 -s 192.168.1.100 -j ACCEPT
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 443 -j DROP