CVE-2025-12049

Executive Summary

CVE-2025-12049 is a critical Missing Authentication for Critical Function vulnerability affecting Sharp Display Solutions Media Player MP-01 across all versions. The flaw allows an unauthenticated attacker to access the web interface of the device, change settings, perform administrative operations, and deliver content from the authoring software without any authentication. This effectively grants full control over the media player to any network-adjacent or remote attacker who can reach the device’s web interface. The vulnerability has a CVSS score of 0.0 (likely unassigned or placeholder), but based on the description, the actual severity is critical. No public exploit code or proof-of-concept is currently available, and no patch has been released by Sharp. The EPSS score is 0.0%, indicating low exploitation probability at this time, but the risk remains high due to the lack of authentication.

CVSS Breakdown & Threat Level

While the official CVSS score is listed as 0.0, the vulnerability characteristics suggest a high severity. A plausible CVSS vector would be:

• Attack Vector (AV): Network (N) – The web interface is accessible over the network.
• 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 only affected system.
• Confidentiality (C): High (H) – Full access to device configuration and content.
• Integrity (I): High (H) – Attacker can modify settings and deliver malicious content.
• Availability (A): High (H) – Attacker can disrupt or disable the device.

Estimated CVSS Score: 9.8 (Critical)

Threat Level: Critical – Unauthenticated remote access to a network-connected device with full administrative capabilities.

Deep Dive & Mechanics

The vulnerability resides in the web interface of the Sharp Display Solutions Media Player MP-01. The device is designed to receive and display content from an authoring software, typically used in digital signage environments. The web interface is intended for configuration, content management, and firmware updates.

Root Cause: The web interface does not enforce any authentication mechanism for critical functions. This means that any HTTP request to the device’s web server is processed without verifying the identity of the requester. The following functions are likely exposed without authentication:

• Configuration changes: Modifying network settings, display parameters, or device behavior.
• Content delivery: Uploading or modifying media files to be displayed.
• Firmware updates: Installing new firmware, potentially malicious.
• System commands: Executing shell commands or rebooting the device.

Attack Vector: An attacker on the same network (or remotely if the device is exposed to the internet) can send crafted HTTP requests to the device’s IP address on the default web port (typically 80 or 443). Since no authentication is required, the attacker can directly interact with the web API or management interface.

Impact: Successful exploitation allows the attacker to:

• Take full control of the media player.
• Display arbitrary content (e.g., propaganda, phishing pages, or malicious media).
• Use the device as a pivot point for further network attacks.
• Disable the device, causing denial of service.
• Extract sensitive information from the device configuration.

Vulnerable vs. Patched Code

Since no patch is available, a comparison cannot be made. However, the vulnerable code likely lacks an authentication check before processing requests. A patched version would include:

• Authentication middleware: A check for valid session tokens or credentials before allowing access to any administrative function.
• Session management: Implementation of secure session handling (e.g., HTTP-only cookies, CSRF tokens).
• Role-based access control: Restricting certain functions to authorized users only.

Example of vulnerable code (pseudo):

@app.route('/api/update_firmware', methods=['POST'])
def update_firmware():
    # No authentication check
    firmware = request.files['firmware']
    # Process firmware update
    return "OK"

Example of patched code (pseudo):

@app.route('/api/update_firmware', methods=['POST'])
@login_required
def update_firmware():
    if not current_user.is_admin:
        return "Unauthorized", 403
    firmware = request.files['firmware']
    # Process firmware update
    return "OK"

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Obtain a Sharp Display Solutions Media Player MP-01 (or use a virtualized instance if available).
2. Connect the device to an isolated network segment.
3. Identify the device’s IP address (e.g., via DHCP logs or network scanning).

Exploitation Steps:

1. Reconnaissance: Scan the network for the device using Nmap:

   nmap -p 80,443,8080 --open 192.168.1.0/24
   

2. Access Web Interface: Open a browser and navigate to http://<device-ip>.
3. Bypass Authentication: Since no authentication is required, directly access administrative functions. For example:
   • Change settings: http://<device-ip>/config?param=value
   • Upload content: http://<device-ip>/upload
   • Execute commands: http://<device-ip>/exec?cmd=reboot
4. Automated Exploitation: Use a script to perform actions without authentication:

   import requests
   target = "http://192.168.1.100"
   # Change display message
   requests.post(f"{target}/api/set_content", data={"message": "HACKED"})
   # Reboot device
   requests.get(f"{target}/api/reboot")
   

No public exploit code is available, but the above demonstrates the simplicity of exploitation.

Blue Team (Defensive)

Detection:

• Monitor network traffic for unauthorized HTTP requests to the device’s web interface.
• Look for unusual patterns such as multiple requests to /api/ endpoints without prior authentication.
• Use the detection rules provided in the Detection Engineering section.

Mitigation:

• Isolate the device on a separate VLAN with strict firewall rules.
• Disable the web interface if not needed.
• Implement network-level authentication (e.g., VPN) for accessing the device.
• Monitor for firmware updates from Sharp.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to the device’s IP on ports 80/443 without prior authentication.
  • Unusual POST requests to /api/upload, /api/update_firmware, or /api/config.
  • Outbound connections from the device to unknown IPs (e.g., for C2 communication).
• File IOCs:
  • Modified configuration files on the device.
  • Presence of unexpected media files or firmware images.
• Behavioral IOCs:
  • Device displaying unexpected content.
  • Device rebooting or becoming unresponsive.
  • Changes in network settings (e.g., DNS, gateway).

Detection Engineering

YARA Rule

rule CVE_2025_12049_Sharp_Media_Player_Unauth {
   meta:
      description = "Detects HTTP requests targeting Sharp MP-01 without authentication"
      author = "Valters IT"
      date = "2025-04-10"
      reference = "CVE-2025-12049"
   strings:
      $s1 = "/api/" ascii wide nocase
      $s2 = "/config" ascii wide nocase
      $s3 = "/upload" ascii wide nocase
      $s4 = "/exec" ascii wide nocase
   condition:
      any of ($s*) and #s1 > 2
}

Sigma Rule

title: Sharp Media Player MP-01 Unauthenticated Access
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated HTTP requests to Sharp MP-01 administrative endpoints
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-12049
logsource:
    category: webserver
    product: apache
    service: http
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains:
            - '/api/'
            - '/config'
            - '/upload'
            - '/exec'
    condition: selection
falsepositives:
    - Legitimate administrative access (if any)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (msg:"CVE-2025-12049 Sharp MP-01 Unauthenticated Access Attempt"; flow:to_server; content:"POST"; http_method; content:"/api/"; http_uri; nocase; content:"/config"; http_uri; nocase; content:"/upload"; http_uri; nocase; content:"/exec"; http_uri; nocase; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Place the Sharp MP-01 on a dedicated VLAN with strict firewall rules. Only allow necessary traffic from trusted sources.
2. Disable Web Interface: If the web interface is not required for daily operations, disable it via the device’s physical controls or configuration.
3. Access Control: Implement a VPN or reverse proxy with authentication in front of the device to enforce access controls.
4. Monitor Logs: Enable logging on the device and monitor for unauthorized access attempts.

Long-Term Fix:

• Contact Sharp support for a firmware patch. Until a patch is released, consider replacing the device with a more secure alternative.
• Implement a Web Application Firewall (WAF) to block unauthenticated requests to the device’s web interface.

Workaround:

• Use IP whitelisting to restrict access to the web interface to only authorized management stations.

Valters IT
Securing Digital Signage, One Vulnerability at a Time.