CVE-2025-11642

Executive Summary

CVE-2025-11642 identifies a denial of service (DoS) vulnerability in the Registration Handler component of Tomofun Furbo 360 and Furbo Mini pet cameras. The attack requires physical access to the device and is considered difficult to exploit due to high complexity. The vendor has not responded to disclosure attempts, and no patch is currently available. This vulnerability could allow an attacker with physical proximity to render the device inoperable, disrupting its core functionality as a pet monitoring camera.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, indicating that no official CVSS vector has been assigned by NVD. However, based on the description (physical access required, high complexity, denial of service), a reasonable estimated vector would be:

• Attack Vector (AV): Physical (P)
• Attack Complexity (AC): High (H)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): None (N)
• Integrity (I): None (N)
• Availability (A): High (H)

Estimated CVSS:3.1 Vector: AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Estimated Base Score: 3.9 (Low)

Threat Level: Low to Moderate. The requirement for physical access and high complexity reduces the likelihood of widespread exploitation, but the lack of a patch means affected devices remain vulnerable indefinitely.

Deep Dive & Mechanics

The vulnerability resides in the Registration Handler of the Furbo 360 and Furbo Mini firmware. The Registration Handler is responsible for initial device setup and pairing with the Tomofun cloud service. By manipulating this handler through physical interaction (e.g., pressing buttons, connecting to debug ports, or exploiting a local interface), an attacker can trigger a condition that leads to a denial of service.

The exact mechanism is not publicly disclosed, but based on the CWE-400 (Uncontrolled Resource Consumption) classification, it likely involves:

• Sending malformed or excessive registration requests that exhaust device memory or CPU.
• Exploiting a race condition during the registration process.
• Triggering a firmware crash by providing invalid input to the handler.

The attack is "difficult" because it requires precise timing, specialized knowledge of the device's internal interfaces, or custom hardware to interact with the registration process.

Vulnerable vs. Patched Code

No patch is available. The vulnerable code resides in the firmware binaries for:

• Furbo 360: up to version FB0035_FW_036
• Furbo Mini: up to version MC0020_FW_074

Without vendor cooperation, a code-level comparison is not possible. The vulnerability is presumed to be in the registration logic, which may involve:

• Input validation failures
• Improper state management
• Resource exhaustion during device pairing

Exploitation & Lab Setup

Red Team

Prerequisites:

• Physical access to a vulnerable Furbo 360 or Furbo Mini device.
• Knowledge of the device's debug interfaces (e.g., UART, JTAG) or ability to interact with the registration button sequence.
• Custom firmware analysis tools (e.g., binwalk, Ghidra) to identify the vulnerable function.

Exploitation Steps:

1. Power on the device and enter registration mode (typically by holding a button or using a factory reset sequence).
2. Intercept the registration communication (e.g., via a serial console or network traffic).
3. Send a crafted payload that triggers the DoS condition. For example, sending an oversized or malformed registration packet.
4. Observe the device become unresponsive or reboot in a loop.

Example Payload (Conceptual):

import socket
import time

# Assuming the device listens on a local port during registration
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('192.168.1.100', 8888))  # Example IP and port
payload = b'\x00' * 65535  # Oversized packet
sock.send(payload)
sock.close()

Blue Team

Detection:

• Monitor for unexpected device reboots or unavailability during registration.
• Log physical access attempts to the device (e.g., via surveillance cameras).
• Use network monitoring to detect anomalous traffic patterns from the device during setup.

Mitigation:

• Isolate the device on a separate VLAN with strict access controls.
• Disable physical debug interfaces (e.g., UART) if possible.
• Implement a hardware-based watchdog to reset the device if it becomes unresponsive.

Indicators of Compromise (IOCs)

• Network: Unusually large or malformed packets sent to the device during registration.
• System: Device repeatedly rebooting or failing to complete registration.
• Physical: Signs of tampering with the device casing or debug ports.
• Firmware: Unexpected changes to the device's firmware version or configuration.

Detection Engineering

YARA Rule

rule CVE_2025_11642_Furbo_DoS {
    meta:
        description = "Detects firmware images vulnerable to CVE-2025-11642"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-11642"
    strings:
        $fw360 = "FB0035_FW_036" ascii wide
        $fwmini = "MC0020_FW_074" ascii wide
    condition:
        $fw360 or $fwmini
}

Sigma Rule

title: CVE-2025-11642 Furbo DoS Exploitation Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects potential exploitation of CVE-2025-11642 via anomalous registration traffic
author: Valters IT
logsource:
    category: network
    product: suricata
detection:
    selection:
        - payload_length: > 10000
        - event_type: "alert"
    condition: selection
falsepositives:
    - Legitimate firmware updates
level: high

Suricata Rule

alert tcp any any -> $HOME_NET 8888 (msg:"CVE-2025-11642 Furbo DoS Attempt"; flow:to_server; content:"|00|"; depth:1; byte_test:1,>,100,0; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Physical Security: Restrict physical access to Furbo devices. Place them in secure locations where unauthorized individuals cannot interact with them.
2. Network Segmentation: Place the device on a separate VLAN with no direct internet access unless necessary.
3. Firmware Monitoring: Regularly check for firmware updates from Tomofun. If a patch becomes available, apply it immediately.

Long-Term Recommendations:

• Vendor Engagement: Continue to pressure Tomofun to release a security patch. Consider escalating through responsible disclosure channels or regulatory bodies.
• Device Replacement: If no patch is forthcoming, consider replacing the device with a more secure alternative.
• Hardware Hardening: Disable unused physical interfaces (e.g., UART, JTAG) by removing jumpers or applying epoxy.

Workarounds:

• Disable the registration handler if the device is already configured and does not need to be re-paired.
• Use a firewall to block all inbound traffic to the device except from trusted management hosts.

Valters IT