CVE-2023-43844

Executive Summary

CVE-2023-43844 exposes a critical security flaw in the Aten PE6208 Power Distribution Unit (PDU). The device ships with hardcoded default credentials for the privileged web interface account, and critically, the user is not prompted to change these credentials upon initial login. This oversight allows any attacker who can reach the web interface to authenticate with the default credentials and gain full administrative control over the device. The vulnerability is classified as CWE-798 (Use of Hard-coded Credentials) and is trivially exploitable, requiring no prior authentication or user interaction. Given the device's role in managing power to critical infrastructure, this represents a severe risk of unauthorized access, denial of service, and potential lateral movement within a network.

Supply Chain & Package Security

This vulnerability is not related to a software package manager (NPM, PyPI, Go, Ruby). It is a firmware-level issue in an embedded device (Aten PE6208 PDU). The risk is introduced at the hardware procurement and deployment stage, where default credentials are not changed by the deploying organization.

CVSS Breakdown & Threat Level

• CVSS Score: 10.0 (Critical)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Attack Vector (AV): Network - The vulnerability is exploitable remotely over the network.
• Attack Complexity (AC): Low - No special conditions or complex attack sequences are required.
• Privileges Required (PR): None - No authentication is needed to exploit the default credentials.
• User Interaction (UI): None - The victim does not need to perform any action.
• Scope (S): Unchanged - The vulnerable component and the impacted component are the same.
• Confidentiality (C): High - Full access to device configuration, logs, and potentially network data.
• Integrity (I): High - An attacker can modify device settings, firmware, and power management rules.
• Availability (A): High - An attacker can power cycle outlets, causing a denial of service to connected equipment.

Threat Level: Critical. The combination of network exploitability, no required privileges, and high impact makes this a top-priority vulnerability for any organization using the affected device.

Deep Dive & Mechanics

The Aten PE6208 is a managed PDU that provides remote power monitoring and control via a web interface. The vulnerability stems from the device's firmware (versions 2.3.228 and 2.4.232) containing a pre-configured administrative account with a known, hardcoded password. The web interface's authentication mechanism does not enforce a password change on the first login, nor does it check if the default credentials are still in use after the initial setup.

The attack flow is straightforward:

1. Discovery: An attacker scans for devices with the Aten PE6208 web interface exposed on the network (typically on port 80 or 443).
2. Authentication: The attacker navigates to the login page and enters the default username and password (e.g., admin/admin or administrator/password).
3. Authorization: The web server validates the credentials against the hardcoded values and grants the attacker a session with full administrative privileges.
4. Exploitation: Once logged in, the attacker can:
   • View and modify all device settings.
   • Control individual power outlets (on/off/reboot).
   • Access network configuration, potentially pivoting to other internal systems.
   • Upload malicious firmware or configuration files.
   • Disable logging or alter audit trails.

The core issue is not a buffer overflow or injection flaw, but a fundamental failure in secure product design: the use of static, unchangeable default credentials without a forced password reset mechanism.

Vulnerable vs. Patched Code

Since no official patch has been released, there is no "patched" code to compare. The vulnerable code resides in the web server's authentication module within the firmware. The logic is essentially:

Vulnerable (Firmware 2.3.228 / 2.4.232):

// Pseudo-code for the authentication check
bool authenticate(char *username, char *password) {
    if (strcmp(username, "admin") == 0 && strcmp(password, "admin") == 0) {
        return true; // Grants admin access
    }
    // ... other user checks ...
    return false;
}

Patched (Hypothetical):

// Pseudo-code for a secure implementation
bool authenticate(char *username, char *password) {
    // Check if default credentials are still in use
    if (is_default_credentials(username, password)) {
        return false; // Force password change
    }
    // ... proper hashed password verification ...
    return verify_password_hash(username, password);
}

The absence of a patch from Aten means the only mitigation is manual intervention by the device administrator.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Target: An Aten PE6208 PDU with firmware version 2.3.228 or 2.4.232, accessible on the network.
2. Attacker: A Kali Linux machine on the same network segment.

Exploitation Steps:

1. Identify the device: Use Nmap to scan for the web interface.

   nmap -p 80,443 --open -sV 192.168.1.0/24
   

2. Access the login page: Open a browser and navigate to http://<PDU_IP>.
3. Login with default credentials: Enter admin for both username and password.
4. Confirm admin access: The web interface should now display the full administrative dashboard.

Automated Exploit (Python):

import requests

target_ip = "192.168.1.100"
login_url = f"http://{target_ip}/login.cgi"
payload = {"username": "admin", "password": "admin"}

session = requests.Session()
response = session.post(login_url, data=payload)

if "Dashboard" in response.text or response.status_code == 200:
    print("[+] Successfully logged in with default credentials!")
    # Now you can interact with the device's API
else:
    print("[-] Login failed.")

Blue Team (Defensive)

Detection & Response:

1. Network Monitoring: Look for repeated login attempts to the PDU's web interface, especially with common default usernames (admin, root, administrator).
2. Log Analysis: Check the PDU's internal logs (if accessible) for successful logins from unexpected IP addresses or at unusual times.
3. Configuration Audit: Regularly audit all PDUs to ensure default credentials have been changed. Use a configuration management tool to enforce this.
4. Network Segmentation: Place PDUs on a separate management VLAN with strict access control lists (ACLs) to limit exposure.
5. Honeypot: Deploy a fake PDU web interface to detect scanning and exploitation attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /login.cgi with username=admin and password=admin.
  • Successful HTTP 200 responses from the PDU's web interface followed by requests to administrative endpoints (e.g., /config.cgi, /outlet.cgi).
  • Source IP addresses not in the authorized management subnet.
• Host IOCs (on the PDU):
  • Unauthorized changes to outlet power states.
  • Modified network configuration (DNS, gateway, etc.).
  • Presence of unknown firmware or configuration files.
• File IOCs:
  • N/A (embedded device, no traditional file system).

Detection Engineering

YARA Rule

rule CVE_2023_43844_Aten_Default_Creds {
    meta:
        description = "Detects network traffic containing default Aten PE6208 credentials"
        author = "Valters IT"
        date = "2024-05-24"
        reference = "CVE-2023-43844"
    strings:
        $login_path = "/login.cgi"
        $default_user = "username=admin"
        $default_pass = "password=admin"
    condition:
        all of them
}

Sigma Rule

title: CVE-2023-43844 - Aten PE6208 Default Credential Login Attempt
id: 8a4b3c2d-1e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP POST requests to Aten PE6208 login page with default credentials.
author: Valters IT
date: 2024-05-24
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/login.cgi'
        cs-username: 'admin'
        cs-password: 'admin'
    condition: selection
falsepositives:
    - Legitimate administrative actions if default creds are still in use (should be investigated)
level: critical

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2023-43844 - Aten PE6208 Default Credential Login Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/login.cgi"; http_uri;
    content:"username=admin"; http_client_body;
    content:"password=admin"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
    reference:cve,2023-43844;
)

Remediation & Mitigation

Immediate Actions:

1. Change Default Credentials: Immediately log into every Aten PE6208 device and change the default username and password to a strong, unique credential.
2. Network Segmentation: Isolate all PDUs on a dedicated management VLAN with strict firewall rules allowing access only from authorized administrative workstations.
3. Disable Unused Services: If the web interface is not required for management, disable it and use only out-of-band management (e.g., serial console).

Long-Term Actions:

1. Vendor Contact: Contact Aten support to request a firmware patch that enforces a password change on first login.
2. Replace Devices: If a patch is not forthcoming, consider replacing the affected PDUs with models from vendors that follow secure-by-design principles.
3. Continuous Monitoring: Implement monitoring rules (as provided in Detection Engineering) to alert on any default credential usage.
4. Configuration Management: Use a configuration management tool (e.g., Ansible, Puppet) to enforce password policies across all network devices.

Valters IT