CVE-2024-30622: Tenda FH1205 Buffer Overflow Vulnerability

CVE-2024-30622 Overview

CVE-2024-30622 is a critical stack overflow vulnerability affecting the Tenda FH1205 wireless router firmware version 2.0.0.7(775). The vulnerability exists in the mitInterface parameter within the fromAddressNat function, allowing attackers to potentially execute arbitrary code or cause a denial of service condition on affected devices.

Critical Impact

This stack overflow vulnerability enables remote attackers to compromise Tenda FH1205 routers without authentication, potentially leading to complete device takeover, network compromise, or persistent denial of service.

Affected Products

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

Discovery Timeline

• 2024-03-29 - CVE-2024-30622 published to NVD
• 2025-03-13 - Last updated in NVD database

Technical Details for CVE-2024-30622

Vulnerability Analysis

This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow), a memory corruption vulnerability that occurs when user-controlled input is copied to a stack buffer without proper bounds checking. The fromAddressNat function in the Tenda FH1205 firmware fails to validate the length of the mitInterface parameter before processing it, allowing an attacker to overflow the stack buffer.

Stack-based buffer overflows in embedded IoT devices like routers are particularly dangerous because these devices often lack modern memory protection mechanisms such as ASLR (Address Space Layout Randomization) or stack canaries. This makes exploitation more reliable and increases the likelihood of successful remote code execution.

Root Cause

The root cause of CVE-2024-30622 is improper input validation in the fromAddressNat function. When processing the mitInterface parameter, the firmware does not verify that the input length fits within the allocated stack buffer. An attacker can supply an oversized input that overwrites adjacent stack memory, including return addresses and saved registers.

This type of vulnerability is common in embedded systems where developers may prioritize functionality over security, and resource constraints limit the implementation of defensive coding practices.

Attack Vector

The vulnerability is exploitable over the network without requiring authentication. An attacker can send a specially crafted HTTP request to the router's web management interface with a malicious mitInterface parameter value. The oversized parameter triggers the stack overflow condition in the fromAddressNat function.

The attack can be performed remotely from the local network segment, or potentially from the internet if the router's management interface is exposed to external networks. Successful exploitation could result in:

• Remote code execution with root privileges
• Complete router compromise
• Network traffic interception or manipulation
• Persistent backdoor installation
• Denial of service through device crash

Technical details and proof-of-concept information are documented in the GitHub IoT Vulnerability Documentation.

Detection Methods for CVE-2024-30622

Indicators of Compromise

• Unexpected router reboots or crashes that may indicate exploitation attempts
• Unusual outbound network traffic from the router to unknown IP addresses
• Modified router configuration or unexpected firewall rule changes
• Presence of unknown processes or services running on the device
• Anomalous HTTP requests to the router management interface containing oversized parameters

Detection Strategies

• Monitor HTTP traffic to the router management interface for abnormally large mitInterface parameter values
• Implement network intrusion detection rules to identify stack overflow exploitation patterns
• Deploy anomaly detection to flag unusual traffic patterns from router devices
• Review router logs for repeated crashes or service restarts that may indicate exploitation attempts

Monitoring Recommendations

• Enable logging on all network infrastructure devices and forward logs to a centralized SIEM
• Implement network segmentation to isolate IoT and router devices from critical network segments
• Deploy network traffic analysis tools to identify suspicious communication patterns
• Establish baseline behavior for router devices to detect anomalies

How to Mitigate CVE-2024-30622

Immediate Actions Required

• Restrict access to the router management interface to trusted IP addresses only
• Disable remote management features if not required
• Place the router behind a firewall that filters malicious traffic
• Consider replacing the affected device if no firmware update is available from Tenda
• Monitor the device for signs of compromise

Patch Information

At the time of this writing, no vendor advisory or official patch has been published by Tenda for this vulnerability. Organizations should monitor Tenda's official support channels for firmware updates that address CVE-2024-30622. Given the critical severity of this vulnerability, affected organizations should consider replacement devices if patches are not made available in a timely manner.

Workarounds

• Disable the web management interface entirely if not needed for operations
• Implement strict access control lists (ACLs) to limit management interface access to specific trusted hosts
• Deploy a web application firewall (WAF) or intrusion prevention system (IPS) in front of the device to filter malicious requests
• Isolate affected devices on a separate network segment with enhanced monitoring
• Consider deploying alternative router hardware from vendors with better security update practices

# Example: Restrict management interface access via firewall rules
# Block external access to router management ports
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP