CVE-2024-30593: Tenda FH1202 Buffer Overflow Vulnerability

CVE-2024-30593 Overview

CVE-2024-30593 is a stack overflow vulnerability affecting the Tenda FH1202 wireless router firmware version 1.2.0.14(408). The vulnerability exists in the deviceName parameter of the formSetDeviceName function, which fails to properly validate input length before copying data to a fixed-size stack buffer. This classic buffer overflow condition can be exploited remotely over the network without authentication, potentially allowing attackers to execute arbitrary code or cause denial of service on affected devices.

Critical Impact

This vulnerability allows unauthenticated remote attackers to potentially achieve code execution on vulnerable Tenda FH1202 routers by sending specially crafted requests to the formSetDeviceName function, compromising the integrity, confidentiality, and availability of the device.

Affected Products

• Tenda FH1202 Firmware version 1.2.0.14(408)
• Tenda FH1202 Hardware

Discovery Timeline

• 2024-03-28 - CVE-2024-30593 published to NVD
• 2025-03-13 - Last updated in NVD database

Technical Details for CVE-2024-30593

Vulnerability Analysis

The vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), a classic memory corruption issue commonly found in embedded systems and IoT devices. The formSetDeviceName function processes user-supplied input through the deviceName parameter but fails to implement proper bounds checking before copying data to a stack-allocated buffer.

When a user sends a request to set the device name, the function directly copies the input to a fixed-size buffer on the stack. If an attacker provides input exceeding the expected buffer size, the overflow can overwrite adjacent stack memory, including saved return addresses and other critical data structures.

The network-accessible attack vector combined with no authentication requirements makes this vulnerability particularly dangerous for internet-facing routers. Successful exploitation could allow an attacker to hijack program execution flow, potentially leading to complete device compromise.

Root Cause

The root cause is improper input validation in the formSetDeviceName function. The function uses an unsafe copy operation that does not verify the length of the deviceName parameter before writing it to a stack buffer. This is a common vulnerability pattern in embedded firmware where memory-constrained environments lead to the use of fixed-size buffers without corresponding size checks.

Attack Vector

The attack is conducted remotely over the network. An attacker can send a maliciously crafted HTTP request to the router's web management interface containing an oversized deviceName parameter. Since the vulnerability requires no privileges and no user interaction, any attacker with network access to the router's administration interface can attempt exploitation.

The attack flow typically involves:

1. Identifying a vulnerable Tenda FH1202 router on the network
2. Crafting an HTTP request to the formSetDeviceName endpoint with an oversized deviceName parameter
3. The overflow corrupts stack memory, potentially overwriting return addresses
4. Depending on exploitation sophistication, this could lead to denial of service or arbitrary code execution

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

Detection Methods for CVE-2024-30593

Indicators of Compromise

• Unusual HTTP requests to the router's web interface with abnormally long deviceName parameters
• Router crashes or unexpected reboots following web interface access
• Unexplained changes to device configuration or firmware behavior
• Network traffic anomalies indicating potential command and control communication from the router

Detection Strategies

• Monitor HTTP traffic to router management interfaces for requests with oversized parameters exceeding normal device name lengths
• Implement network intrusion detection rules to flag unusually large POST requests to /goform/SetDeviceName or similar endpoints
• Deploy firmware integrity monitoring to detect unauthorized modifications
• Set up alerting for repeated router reboots or service interruptions

Monitoring Recommendations

• Enable logging on network firewalls and review access attempts to router management ports (typically 80/443)
• Segment IoT and network infrastructure devices from general network traffic to limit exposure
• Implement regular vulnerability scanning of network devices to identify outdated firmware versions
• Consider deploying a dedicated IoT security monitoring solution for embedded device anomaly detection

How to Mitigate CVE-2024-30593

Immediate Actions Required

• Restrict access to the router's web management interface to trusted internal networks only
• Disable remote administration features if not required
• Place the router behind a firewall that blocks external access to management ports
• Monitor for any available firmware updates from Tenda and apply immediately when released

Patch Information

As of the last NVD update on 2025-03-13, no official patch has been documented in the available advisory information. Users should regularly check Tenda's official support channels for firmware updates addressing this vulnerability. The GitHub IoT Vulnerability Documentation provides additional technical details about the vulnerability.

Workarounds

• Disable the web-based management interface entirely if device management is not required
• Implement network segmentation to isolate the router from untrusted networks
• Use access control lists (ACLs) to restrict management interface access to specific trusted IP addresses
• Consider replacing the affected device with a model that receives active security updates

# Example: Restrict management access using iptables on upstream firewall
# Block external access to router management interface (adjust IP as needed)
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 -j DROP
# Allow only specific trusted management workstation
iptables -I FORWARD -s 192.168.1.100 -d 192.168.1.1 -p tcp --dport 80 -j ACCEPT