CVE-2024-41196

Executive Summary

CVE-2024-41196 is a critical authentication bypass vulnerability in Ocuco Innovation's REPORTSERVER.EXE version 2.10.24.13. An unauthenticated attacker can send a crafted TCP packet to the service, bypassing all authentication mechanisms and escalating privileges to Administrator. This allows full remote control over the affected system, including data exfiltration, lateral movement, and potential ransomware deployment. No public proof-of-concept (PoC) or patch is currently available, making this a high-risk zero-day for organizations using this software.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official vector assigned)
• 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) – Exploit stays within the vulnerable component.
• Confidentiality (C): High (H) – Full data access.
• Integrity (I): High (H) – Full system modification.
• Availability (A): High (H) – Potential denial of service or full control.
• Threat Level: Critical – Remote, unauthenticated, privilege escalation to Administrator.

Deep Dive & Mechanics

The vulnerability resides in the REPORTSERVER.EXE service, which listens on a TCP port (likely 1433 or a custom port) for incoming connections. The service fails to validate authentication tokens or session credentials before processing commands. By sending a specially crafted TCP packet, an attacker can impersonate an authenticated administrator, bypassing all access controls.

The root cause is a missing authentication check in the packet handling logic. The service likely uses a simple binary protocol where a specific byte sequence or flag triggers administrative functions without verifying the sender's identity. This is a classic CWE-306 (Missing Authentication for Critical Function) vulnerability.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the entire REPORTSERVER.EXE binary. The patched version would require adding authentication checks before processing any administrative commands.

Vulnerable Code (Conceptual):

void handle_packet(Packet *pkt) {
    // No authentication check
    if (pkt->command == ADMIN_CMD) {
        execute_admin(pkt->data);
    }
}

Patched Code (Conceptual):

void handle_packet(Packet *pkt) {
    if (!authenticate(pkt->token)) {
        send_error(pkt->source, "Authentication failed");
        return;
    }
    if (pkt->command == ADMIN_CMD) {
        execute_admin(pkt->data);
    }
}

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Install Ocuco Innovation REPORTSERVER.EXE v2.10.24.13 on a Windows VM.
2. Ensure the service is running and listening on TCP port 1433 (or discoverable via netstat).
3. Use a tool like Python or Scapy to craft a TCP packet with a specific payload that triggers the admin bypass.

Exploit Script (Python):

import socket

target_ip = "192.168.1.100"
target_port = 1433

# Crafted packet to bypass authentication (hypothetical)
payload = b"\x00\x01\x02\x03"  # Replace with actual magic bytes
payload += b"ADMIN_CMD"        # Command to escalate privileges

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((target_ip, target_port))
sock.send(payload)
response = sock.recv(4096)
print(response)
sock.close()

Expected Outcome: The service executes the command with Administrator privileges, allowing full system control.

Blue Team

Detection:

• Monitor for unusual TCP connections to the REPORTSERVER port from unknown IPs.
• Look for anomalous packet sizes or patterns that deviate from normal traffic.
• Enable logging on the REPORTSERVER service to capture all incoming commands.

Hunting:

• Search for processes spawning from REPORTSERVER.EXE with high integrity levels.
• Check for new user accounts or scheduled tasks created by the service.

Indicators of Compromise (IOCs)

• Network: TCP connections to port 1433 (or custom port) from external IPs.
• File: Unusual files created in C:\Program Files\Ocuco\Reports\ or C:\Windows\Temp\.
• Process: REPORTSERVER.EXE spawning cmd.exe or powershell.exe.
• Registry: New entries under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run.
• Log: Event ID 4624 (successful logon) for Administrator account from unexpected source.

Detection Engineering

YARA Rule

rule CVE_2024_41196_REPORTSERVER_BYPASS {
    meta:
        description = "Detects crafted TCP packets targeting REPORTSERVER.EXE"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-41196"
    strings:
        $magic = { 00 01 02 03 }  // Replace with actual magic bytes
        $admin_cmd = "ADMIN_CMD"
    condition:
        $magic at 0 and $admin_cmd
}

Sigma Rule

title: CVE-2024-41196 REPORTSERVER Authentication Bypass
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects exploitation attempts against REPORTSERVER.EXE
author: Valters IT
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        DestinationPort: 1433
        Initiated: true
    condition: selection
falsepositives:
    - Legitimate REPORTSERVER traffic
level: high

Suricata Rule

alert tcp any any -> any 1433 (msg:"CVE-2024-41196 REPORTSERVER Authentication Bypass"; content:"|00 01 02 03|"; content:"ADMIN_CMD"; distance:0; within:100; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: Isolate the REPORTSERVER service behind a firewall, allowing only trusted IPs.
• Short-term: Disable the service if not critical, or apply network segmentation.
• Long-term: Contact Ocuco for an official patch. If unavailable, consider replacing the software.
• Compensating Controls: Deploy an IDS/IPS with the Suricata rule above. Enable Windows Defender Application Control (WDAC) to block unauthorized executables.

Valters IT
Securing Digital Frontiers